What is screen time defined as?

"Screen time" is a term used for activities done in front of a screen, such as watching TV, working on a computer, or playing video games.

What is a healthy screen time? [1]

Health experts say screen time at home should be limited to two hours or less a day. The time we spend in front of the screen, unless it's work- or homework-related, could be better spent being more physically active (increasing our energy out).

How much screen time by age?

Recommended time limits

• Under 2 years old: Zero screen time, except for video chatting with family or friends.
• 2-5 years old: No more than one hour per day co-viewing with a parent or sibling.
• 5-17 years old: Generally no more than two hours per day, except for homework.

Screen time is a sedentary activity, meaning you are being physically inactive while sitting down. Very little energy is used during screen time.

Most American children spend about 3 hours a day watching TV. Added together, all types of screen time can total 5 to 7 hours a day.

Can mobile cause astigmatism?

For example, prolonged and frequent use of electronic devices such as smartphones, laptops, and tablets can cause eye strain and fatigue, leading to worsening astigmatism symptoms. Excessive exposure to UV rays from the sun or bright lights can also contribute to the development and progression of astigmatism.[2]

Too much screen time can:

• Make it hard for your child to sleep at night
• Raise your child's risk for attention problems, anxiety, and depression
• Raise your child's risk for gaining too much weight (obesity)

Screen time increases your child's risk for obesity because:

• Sitting and watching a screen is time that is not spent being physically active.
• TV commercials and other screen ads can lead to unhealthy food choices. Most of the time, the foods in ads that are aimed at kids are high in sugar, salt, or fats.
• Children eat more when they are watching TV, especially if they see ads for food.

Computers can help kids with their schoolwork. But surfing the internet, spending too much time on Facebook, or watching YouTube videos is considered unhealthy screen time.

How to Decrease Screen Time

Cutting down to 2 hours a day can be hard for some children because TV may be such a large part of their daily routines. But you can help your children by telling them how sedentary activities affect their overall health. Talk to them about things they can do to be healthier.

To decrease screen time:

• Remove the TV or computer from your child's bedroom.
• Do not allow TV watching during meals or homework.
• Do not let your child eat while watching TV or using the computer.
• Do not leave the TV on for background noise. Turn on the radio instead, or have no background noise.
• Decide which programs to watch ahead of time. Turn off the TV when those programs are over.
• Suggest other activities, such as family board games, puzzles, or going for a walk.
• Keep a record of how much time is spent in front of a screen. Try to spend the same amount of time being active.
• Be a good role model as a parent. Decrease your own screen time to 2 hours a day.
• If it is hard not having the TV on, try using a sleep function so it turns off automatically.
• Challenge your family to go 1 week without watching TV or doing other screen-time activities. Find things to do with your time that get you moving and burning energy.

Suicidal thoughts

The most recent study, published in the Journal of Youth and Adolescence, found that girls who had two to three hours of daily screen time beginning at age 13 were more likely to have suicidal thoughts in their later teen years. The same study showed that teenage boys, especially those who were the objects of cyberbullying, were also more likely to have suicidal thoughts in young adulthood.

Another study, published last month in the journal PLOS One, found that teens who spent more than three hours a day for reasons other than school are chronically stressed, sad, and think about suicide more often than those who spend less time with screens, the study showed. They also exhibited more emotional and physical problems.

“The results suggest the need for interventions that increase the awareness of the risks for adolescents who spend an excessive amount of time using the Internet,” the researchers concluded.

Critical thinking

Lead study author Sarah Coyne, associate director of the School of Family Life at Brigham Young University, tells parents not to panic, and not to forbid all screen time outright. Just set reasonable limits, she told the New York Post.

In addition, she encourages her own 13-year-old daughter to think critically and pay attention to the time she spends online.

“We say, ‘When you’re on TikTok, how does it make you feel? Who are you following?’ ” she told the paper. “If it ever feels like they’re bringing you down, or [making] you feel about yourself, you need to think, ‘Maybe I need to take a break,’ or ‘Maybe I need to not follow this person.”

Reference:

1. medlineplus.gov/ency/patientinstructions/000355.htm
2. nhlbi.nih.gov/health/educational/wecan/reduce-screen-time
3. informedfamilies.org/catalyst/the-danger-of-too-much-screen-time-for-teens

See also:

• Manage your child's screen time
• What Causes Astigmatism to Worsen?
• The Danger of Too Much Screen Time for Teens
• Digital Eye Fatigue Can Lead to Lazy Eye in Children

What is screen addiction?

Screen addiction is a group of behaviors that are negative, some negative outcomes that can happen when we use too much technology during our day. So prolonged use of watching TV, video games, scrolling through social media all of that use acts like a digital drug for our brain.

How many hours of screen time is considered an addiction?

How Much Screen Time Is Too Much? The American Optometric Association (AOA) found that people who use screens continuously for two or more hours a day are at the greatest risk of developing computer vision syndrome, the most prevalent side-effect of screen addiction.

Are screens bad for your brain?

Screen time may affect its growth. A study called Adolescent Brain Cognitive Development (ABCD) revealed that some kids who use screens more than seven hours a day had a thinner cortex than those who used screens less. Future studies hope to show how this will affect kids' brains over time.

How much screen time is healthy?

What's a healthy amount of screen time for adults? Experts say adults should limit screen time outside of work to less than two hours per day. Any time beyond that which you would typically spend on screens should instead be spent participating in physical activity.

How much screen time per age?

Yousuf said pediatricians generally recommend the following guidelines: Under 2 years old: Zero screen time, except for video chatting with family or friends.

• 2-5 years old: No more than one hour per day co-viewing with a parent or sibling.
• 5-17 years old: Generally no more than two hours per day, except for homework.

Physical Effects

The most prevalent physical effect of screen use is the great demand it puts on the eyes. Digital eye strain and computer vision syndrome are reported in 50% to 90% of people who work at computers daily.

Symptoms of digital eye strain and computer vision syndrome include:

• Dry eyes
• Blurred vision
• Double vision
• Headaches
• Neck and shoulder pain

While many of these physical symptoms will resolve after screen use has stopped, long-term eye strain can lead to permanent vision problems.

Physiological And Mental Effects

Screen addiction can contribute to physiological and mental effects like insomnia, stress, and depression.

Depression

Depression is the most common mental health condition associated with screen addiction. A study from Preventative Medicine Reports found a correlation between higher screen time usage and moderate to severe depression levels, with higher rates found among females. The study found that four or more hours of daily screen time was the tipping point for heightened risk of depression.

Insomnia And Poor Sleep

Using screens before bed can lead to many issues that affect a person’s sleep quality. Blue light from devices can delay melatonin production, leading to a lack of sleepiness. Likewise, engaging in stimulating games or watching exciting shows can also make a person feel more alert. Screen addiction heightens the risk for these factors, as a person spends excessive time on these devices and puts off sleep.

Stress

Some people claim to use screen time to zone out and take a break from the day’s stressors, but the reality may be that this time is a source of stress. Fear of missing out (FOMO), lowered self-esteem, and loneliness are some of the stressors associated with screen addiction. The Journal of Medical Internet Research found that people who used screen time for entertainment and social networking experienced 19% more emotional stress than those who used screen time for professional purposes.

How To Cut Back Screen Time

If you feel like you are spending too much time looking at a screen, there are methods for cutting back.

20-20-20 Rule

For temporary eye strain relief, the AOA suggests using the 20-20-20 method, which directs a person to take a 20-second break every 20 minutes to focus on an object at least 20 feet away. This gives the eye a break from the blue light and allows it to relax by focusing on something further away.

Time Limits

Many studies recommend limiting personal screen time to 30 minutes per day for optimal effects. Since this may be a drastic change for some, limiting screen use to one hour a day is also beneficial.

Likewise, taking a three-to-four-hour break from screens can create an overall healthier relationship, as the perception changes from looking at screen time as a necessity to an activity of choice.

Digital Detox

A digital detox may be the best option for people who feel like their screen addiction has gotten out of control. This does not necessarily mean giving up all screen use but encourages users to cut back on non-work-related screen time.

Taking scheduled breaks or putting the phone away before bedtime can be the first step in resetting and creating new, healthier relationships with screens.

Treatment Options For Screen Addiction

Screen addiction treatment often involves a mixture of behavioral therapy, support groups, and lifestyle changes.

Lifestyle Changes

Lifestyle changes often include limiting screen time and searching for alternative ways to fill free time, specifically ones that do not involve technology. Finding new hobbies and interests can help reduce dependence on technology. Engaging in social interactions in person is also a great alternative to using smartphones for social interactions. In some cases, prescribed medication may also help address underlying mental health conditions, such as anxiety or depression, that may contribute to screen addiction.

More formal treatment options used to address screen addiction may include:

Cognitive-Behavioral Therapy (CBT)

Cognitive-Behavioral Therapy encourages people to change their thoughts and behaviors related to screen use and addiction. CBT can help individuals develop new and healthy coping skills and habits, identify and address triggers related to screen use, and learn how to utilize their time and energy more appropriately.

Mindfulness-Based Therapy

This type of therapy refers to mindfulness strategies that can help an individual learn to manage stress and anxiety, which are often common triggers for screen use. Practicing mindfulness can teach a person to be more present and aware of their thoughts and feelings. This increased awareness can help individuals reduce their desire for screen time.

Family Therapy

Screen addiction can significantly impact relationships with loved ones. Family therapy can help address these issues. Family therapy can help family members develop healthier communication patterns, boundary setting around screen use, and other ways to support each other in reducing screen time and spending more time with each other.

Group Therapy

Group therapy can offer a supportive and non-judgmental atmosphere for individuals struggling with screen addiction. Individuals can share their coping strategies for managing screen use and gain support from others experiencing the same challenges.

Individual Counseling

Individual counseling can help people get to the root of their problems. There may be a bigger reason why someone has immersed themselves in technology. Individual counseling can help a person address many deep-rooted issues from trauma and relationship problems to grief and loss.

Reference:

• premierhealth.com/your-health/articles/health-topics/screen-addiction-affects-physical-and-mental-health#
• How to Encourage Technology Literacy in Kids Without Screen Addiction? (narayanaschools.in)
• Screen Addiction Explained: Effects and Coping Strategies (addictioncenter.com)

Blue light, which is part of the visible light spectrum, reaches deeper into your eye and its cumulative effect can cause damage to your retina and it is connected to the development of age-related macular degeneration. Blue light is not just entering your eye from natural sources like the sun. Sunlight is the main source of blue light, and exposure outdoors during daylight is the main source for most people.

Blue light lenses have become increasingly popular in our digital age. While there’s no proof they protect against certain eye conditions, there are well-documented benefits, particularly in regulating our sleep-wake cycle.

Hormone Regulation

Exposure to blue light, particularly during the evening, has been shown to disrupt melatonin production, the hormone responsible for regulating our sleep-wake cycle. This disruption can lead to difficulties falling asleep and achieving restful sleep.

Blue light lenses can help mitigate the impact of blue light by limiting how much reaches your eyes, supporting the natural release of melatonin and promoting a more restful and rejuvenating sleep.

There are also many man-made, indoor sources of blue light, including fluorescent and LED lighting, and flat-screen televisions. The display screens of computers, electronic notebooks, smartphones, and other digital devices emit significant amounts of blue light, although it is only a fraction of the amount of blue light emitted by the sun. In a laboratory,sources of blue light are blue LED arrays and intense white light sources (projection lamps, floodlights, microscope lights,welding arcs, etc.).The most common type of LED used in electronic devices is a white-light LED, which actually has a peak emission in the blue wavelength range (400 – 490 nm).

Depression & Anxiety Management

Research has consistently indicated a connection between disrupted sleep and susceptibility to depression and anxiety. Blue light lenses can effectively regulate our sleep-wake cycle and indirectly support mental health. These lenses promote healthier sleep patterns and overall well-being. eResearch by Navid Ajamin -- winter 2017

Blue light lenses may contribute to improved hormone regulation and alertness and provide benefits for managing depression and anxiety.

But blue light lenses are not only helpful for those who spend time in front of digital devices—they can also be beneficial for outdoor use, such as when engaging in activities in direct sunlight. These lenses help reduce glare and make it easier to focus on your activity or enjoy the scenery around you.

Always consult an eye care professional for personalized advice and recommendations regarding your eye health needs.

During daylight, blue wavelengths of light can be beneficial, playing an important role in setting circadian rhythms, boosting attention and mood. But we didn’t evolve to be exposed to it as much as we are. In addition to the ample blue light in sunlight, most of the light we are exposed to via digital devices is also blue.

For example,Moreover, the eye’s cornea and lens are unable to block or reflect blue light.

If you have presbyopia and routinely wear bifocals or progressive lenses, prescription computer glasses give you the additional benefit of a much larger field of view for seeing your entire computer screen clearly. (Keep in mind, though, that this type of computer eyewear is exclusively for seeing objects within arm's length and cannot be worn for driving or other distance vision needs.) Also, a number of lens manufacturers have introduced special glare-reducing anti-reflective coatings that also block blue light from both natural sunlight and digital devices.

Advice when using smartphones and tablets

• Set your device to auto brightness.
• Hold your tablet or smartphone at arm’s length (or about 70cm) from your eyes.
• Make the font bigger to stop strain on the eyes.
• Only use the device for a couple of hours a day in one sitting.Then take a break and come back to it later.

In addition:

• Have your eyes tested regularly and take regular breaks from your computer and hand held device.
• Use good sunglasses with a UV filter when outside.
• Have a healthy and varied diet rich in Vitamin A, lutein, zeaxanthin and mesozeaxanthin which comes from spinach and peppers which will protect the eyes.

Key Points About Blue Light

• Blue light is everywhere.
• HEV light rays make the sky look blue.
• The eye is not very good at blocking blue light.
• Blue light exposure may increase the risk of macular degeneration.
• Blue light contributes to digital eye strain.
• Blue light protection may be even more important after cataract surgery.
• Not all blue light is bad.
• “Health clock” hormones like melatonin are controlled by your body’s exposure to blue light.

Damaging effects of blue light

Too much light in the ultraviolet and blue-violet bands can damage the human eye.

As well as leading to painful inflammation of the conjunctiva and cornea, it can also cause damage to the eye's crystalline lens (e.g. cataracts) and especially to the retina (macular degeneration).

That's why it is so important to wear sunglasses with 100% UV protection in strong sunshine, especially in situations where there is a lot of glare such as on water or snowy mountain
slopes.

According to Harvard researchers, exposure to blue light at night “throws the body’s biological clock—the circadian rhythm—out of whack” and may contribute to an increase of sleeping disorders, blood sugar, hunger, depression, cancer,diabetes, heart disease, and obesity. Blue light during the day helps us feel awake and sets our bodies’ schedule to fall asleep at night, which is critical for migraine sufferers.

All digital devices with viewing screens emit significant amounts of blue light (also called "high-energy visible light" or "HEV light") which might increase a child's risk of macular degeneration later in life.

Blue light glasses were first invented in the 1960s to assist with this growing issue but became popular beginning in the early 2000s. They work by blocking a percentage of blue light with a special coating on the lenses that reflect it away from your eyes.

Founded in Chicago in 1986, BluBlocker Sunglasses made history with a revolutionary lens that reduced brightness while increasing contrast and visibility, using the same groundbreaking technology originally developed for NASA to block harmful UV rays and blue light during space travel.

BlockBlueLight was founded by Daniel Ebbett in 2016, born out of his personal struggle with chronic insomnia and migraines.

What are Z-blue lenses?

Z1 lenses: Z-Blue™ is used for persons who are sensitive to flashing lights and repeating patterns. This lens cuts down on wavelengths from 580-640nm, they reduce the amount of light and filter out red light.

Though the sun emits significantly more HEV light than computers and other digital devices, the added exposure to blue light kids receive from these devices and how close these electronic screens are to a child's eyes for hours each day have many eye care providers worried about potential eye damage over time.

And many eye care practitioners who specialize in children's vision believe prolonged computer use among children puts them at risk for progressive myopia.

Kids and computers are nearly inseparable these days. With many school-age kids and even preschoolers spending hours in front of a computer every day, it's worth considering what effects computers might have on your children's eyes and their vision. When you work at a computer for any length of time, it's common to experience eye strain, blurred vision, red eyes and other symptoms of computer vision syndrome(CVS). This is because the visual demands of computer work are unlike those associated with most other activities.

To reduce the risk of focusing fatigue that can cause advancing nearsightedness among kids who spend a lot of time on a computer, many eye doctors recommend frequent breaks from computer work. Some call this the "20-20-10" rule: Every 20 minutes your child should take
his eyes off the computer and look at an object at least 20 feet away for at least 10 seconds.

Blue Control lenses reduces the symptoms of digital eyestrain such as dry eyes, sticky eyes, and the feeling of grittiness or "sand" in the eye. Protect your lenses against water, dirt, grease and dust, keeping them clean for longer!

The following symptoms are characteristic of someone who uses the computer/phoneset/tablet for a very long period of time:

1. Dry eyes
2. Red eyes
3. Eyestrain
4. Backache
5. Headaches
6. Visual Fatigue
7. Light sensitivity
8. Lower self-esteem
9. Weight gain or loss
10. Progressive myopia
11. Disturbances in sleep
12. Premature presbyopia
13. Loss of cognitive ability
14. Neck and shoulder pain
15. Carpal tunnel syndrome
16. Burning or stinging eyes
17. Impaired socialising skills
18. Leads to screen addiction
19. Weakened emotional judgment
20. Delayed learning in young children
21. Blurred or strained vision/double vision
22. Lack of concentration and focus of mind
23. Susceptibility to chronic health conditions

Which is better blue cut or blue control?

The choice between Blue Cut and Blue Control lenses depends on your specific needs and lifestyle: For Heavy Screen Users: If you spend long hours in front of digital screens, Blue Cut lenses might be the better choice due to their strong blue light blocking capabilities.

Continuous exposure to blue light after sundown can disturb the sleep-wake cycle and make it difficult to fall asleep in the long run. Tinted lenses mimic the conditions of nature by blocking all artificial blue light and regulating a normal sleep-wake cycle, thus promoting good eye-health and sleep.

Is it okay to buy cheap blue light glasses?

Cheap blue light glasses don't target the complete range.

For all we know, the lenses could be ineffective at shielding your eyes from the peak wavelengths.

Reference:
healthrising.org healthline.com health.clevelandclinic.org migrainekey.com ap.lbl.gov/ehs/safety forbes.com/sites/fionamcmillan gundrymd.com/blue-light-warning activesgcircle.gov.sg/activehealth riverheightseyecare.com/what-are-the-benefits-of-blue-light-glasses eyekit.co eyeacademy.com allaboutvision.com reviewofoptometry.com crew.co/blog psychguides.com zeiss.com blockbluelight.com health.harvard.edu/staying-healthy/blue-light-has-a-dark-side

See also:

• Does blue light keep you awake at night?
• How Blue Light Effects Your Eyes and Brain
• Is it bad for your eyes to watch TV too close?
• Is dark mode better or worse for your eyes?
• Is it bad for your eyes to watch TV in the dark?
• Why Is Blue Light before Bedtime Bad for Sleep?
• How Blue Light Could Damage Cells In Your Eyes?
• Pros and Cons of Blue-Cut/Blue-Control Lenses

Visual discomfort is a frequent complaint of computer workers. Eyestrain and headaches blurred vision are the most common problems reported. Other problems include double vision, burning and dry eyes, eye fatigue, light sensitivity, and after-images.

Neck shoulder and back pain can also be related to viewing the computer keyboard and/or screen. The American Optometric Association has designated this complex of problems as computer vision syndrome (CVS).

Lighting and vision are inter-dependent. Workplace lighting and visual ability both play a significant role in work posture. Workers alter postures to relieve stress on the eyes. Complaints of neck, shoulder and back pain can frequently be alleviated if visual ergonomics are addressed.

Vision and Eye Problems:

Difficulties with focusing and eye alignment can result in eyestrain, neck pain and headaches during computer work. To avoid problems, have your vision checked by an eye doctor aware of problems that can interview with computer vision. Make sure you measure the distance you sit from your computer before seeing a doctor. He will need this information to evaluate your need for computer glasses.

Your doctor should check for the following:

• Visual acuity - the ability to see clearly and efficiently at various distances.
• Binocular vision - ability to coordinate eyes by integrate the image recorded by each eye into a single vision.
• Accommodation - the ability of the eyes to shift focus between varying distances. This skill becomes more difficult over the age of 40 due to reduced lens flexibility.
• Oculomotor skills - the ability of the eye muscles to position the eyes correctly to locate and scan text.
• Hyperphoria - tendency of each eye to see objects at different levels. Presence of this disorder results in a tendency to tilt the head to line up things visually, resulting in neck strain.
• Dry eyes – some individuals do not produce enough tear flow to the eyes because of tear duct problems.

Use of Corrective Lenses for Reading or General Activities:

• Contact lenses - Individuals who wear contact lenses blink less than people who have normal vision or wear glasses. Contact wearers must be educated to blink often and use artificial tears to reduce eye irritation. If your eyes are worse using artificial tears, contact your eye doctor to determine if you have a sensitivity or allergy to the product you use.
• Use of glasses designed for reading - Regular glasses are not always suited for computer work. Most monitors are positioned in the intermediate visual zone, rather than in the near or far zones. Reading glasses correct for the near zone, and bifocals correct for only the near and far zones. Trifocals and progressive lenses have only a small portion of the lens corrected for the intermediate zone. This portion is generally not large enough for comfortable computer work.
• Awkward postures - Use of inappropriate glasses can result in blurred vision. Attempts to compensate for blurred vision can encourage awkward postures such as leaning forward. Bifocal users often tilt their necks and heads up to see through the bottom of their glasses. Both of these actions can result in neck aches and backaches.

Monitor Issues:

The type and location of the monitor you use plays a significant role in visual comfort.
Remember that the location of the visual target plays a major role in determining sitting posture. Visual requirements result in the user positioning the body so that the face is parallel to the viewing surface. This principle should be remembered when determining placement of a monitor.

Visual acuity determines the optimal viewing distance to the monitor. Although ANSI and Canadian standards require a minimum viewing distance of 12 inches, research studies have shown a preferred viewing distance of 30 to 40 inches from the screen.

Standards also require that the user’s viewing area should be located between 0 and 60 degrees below the horizontal plane. Recent studies have demonstrated that it is easier to look downward rather than horizontally or upward. Lower targets may be more comfortable for users, especially when preferred viewing distances are considered. These findings suggest that VDT monitors should possibly be located lower and further away from the user than previously thought to offer greatest visual comfort.

Lowering the monitor without angling it up toward the user’s face encourages a forward-thrust head posture. Awkward shoulder, arm, wrist postures results from this compensation. Concern has resulted about the effect of this forward head position and tilted neck. Make sure you adjust the tilt of the monitor to match the height for optimal sitting posture.

For Proper Monitor Placement – Follow these guidelines:

• The screen should be at least 20 to 26 inches distance. Adjust this distance for your visual acuity needs and comfort. The farther away the better in most cases. Distances of 30-40 inches are frequently preferred.
• You should be able to view the screen with a slight downward gaze without tilting your head up or down. The top of the screen should be about at mid-forehead level. If you have a screen larger than 17”, the top of the screen may need to be a little higher.
• Your face should be parallel to the screen. Setting the tilt will help to adjust the height. Be sure to test for excessive glare when tilting the screen. If you can see your image in the screen, reflections and glare will strain your eyes while working.
• Your documents should be positioned close to the monitor, either close to the side or directly in front between the keyboard and the screen.

Brightness and Contrast – The monitor’s brightness should match the room brightness. Begin making adjustments by reducing glare from sources in the room such as windows and overhead lights. Use light switches, blinds, curtains, filters or remove bulbs as necessary. Then adjust the brightness control on the monitor somewhere close to the monitor’s mid-range if possible. After adjusting the brightness, set the contrast to a comfortable level. Usually, the higher the contrast the better.

Display Quality – The clarity of your screen depends upon refresh rate, resolution and dot pitch.

• Refresh rate refers to how often your monitor redraws the screen. Slow rates can cause a noticeable flicker. People vary in their sensitivity to flicker. Your refresh rate should be at least 70 Hz (hertz) or higher.
• Resolution refers to the monitor’s pixel density and determines the level of detail. The higher the resolution, the better the detail. 800 x 600 is recommended. Make sure you don’t sacrifice the refresh rate for resolution. They are related to each other and should both be high for good quality.
• Dot pitch determines sharpness of the display. The lower the dot pitch number, the sharper the image. Select a monitor with a dot pitch or .28 mm (millimeters) or lower. (If your dot pitch is listed as horizontal or stripe pitch, divide it by 0.866 to determine the equivalent regular dot pitch.)

Check your refresh rate and resolution for adjustment if necessary. They can be adjusted using the Settings tab in the Display properties dialog box in Windows.
Dot pitch is not adjustable.

Computer Glasses

Computer glasses correct your vision in the intermediate zone, the distance you normally sit from your computer screen. If you also require correction in the near and/or far zones, you will need to consider multiple focusing options.

• Lens design - There are several types of computer lenses available. They range from occupational progressive lenses and trifocals with larger than normal intermediate zones, to single-vision (intermediate) lenses. Specially designed bifocals or computer prescriptions that clip-on to your regular eyeglasses are also available. Your eye doctor can help you decide which lens design you need.
• Tints and coatings - Computer lenses can be tinted to help with reducing eyestrain from excessive glare from windows or fluorescent overhead lights. Antireflective coating or ultraviolet coatings and amber tints can all help relieve eyestrain.

Health Problems Caused by Computers

Technology has become an inseparable part of our lives and has become a necessity in almost every field of work. With that said, it seems also as if there are consistent technological changes and advancements with the ultimate goal of making certain tasks completely rely on the use of technology. Of course it makes our lives easier in some ways and maybe even less expensive, but it can be rather frustrating too.

Does your occupation require you to spend an extended amount of time in front of the computer…say over 4 hours a day? If so, you could be at an increased risk of developing certain health problems including the following:

1. Musculoskeletal Problems eResearch by Navid Ajamin -- winter 2017

• This includes areas of your body such as your back, neck, chest, arms, shoulders and feet.
• Having sore muscles and complaints of the muscles being tired are common.
• Numbness may occur in the arms and hands.
• These troubles may occur because the posture you assume when using the computer is most likely incorrect.
• You may find that you are sitting in an uncomfortable chair, or that you have a workstation that is not ergonomically correct for your body.

Tips to Consider

• Find a correct height for both your desk and chair so that your computer screen is at eye level or slightly lower.
• Sit with your back straight, legs at 90 degree angles to the floor, and feet resting flat on the floor.
• ALWAYS take small breaks from your computer work to stretch your muscles, keep your blood flowing, and to rest your eyes.

2. Vision Problems

• Computers are notorious for their bright lights, glare and flickering images that can cause strain on your eyes.
• Finding that you constantly focusing on the screen with delays in blinking can result in drying out your eyes.

Tips to Consider

• Make sure to adjust the brightness on your computer screen so that your eyes are not as strained. For example, if you are sitting in a dark room your computer screen will most likely be very bright and cause your eyes to strain, so to save your eyes you should lower the brightness.
• Tilt your screen to decrease any glare.
• Maintain a proper vision distance from the screen, and do not forget to blink.

3. Repetitive Stress Injuries

• You may notice pain in your neck, shoulders, or really anywhere from the shoulders to your fingers related to repetitive muscle use.
• Using the computer may cause you to use your muscles in an odd way that may cause increased stiffness, pain, or swelling in any of those areas.
• One of the most common conditions related to repetitive use of your muscles when using the computer is carpal tunnel syndrome.

Tips to Consider

• Place your mouse at a location next to the keyboard that will require you to move your whole arm to get to it rather that just twisting your wrist outward to reach it and move it.
• Type gentle to decrease the stress put on each of your fingers.
• Keep your wrists flexible when typing; avoid keeping them fixed in a certain position; keeping them flexible will avoid repetitive, strenuous stress.
• Relax your arms and try to get a few stretches in when you are not typing or using your mouse.

4. Headaches

• Headaches are common and may occur because of the increased muscle tension or from pain in the neck.
• Any vision problems, or continued strain on the eyes can also cause headaches.

Tips to Consider

• Attend regular eye exams in order to work toward correcting any vision problems.
• Try your best to keep your neck straight in front of the computer and take breaks.

5. Obesity

• Prolonged use of computers may lead to an overall sedentary lifestyle that lacks adequate physical activity and/or exercise.
• In children prolonged use of computers, or electronics in general, is a major contributing factor to obesity.

Tips to Consider

• Set limits for your children when they are using electronics.
• Encourage outdoor play or a certain hobby that may take away time spent using electronics in order to lead a more active lifestyle.
• As for adults, if your occupation requires computer use for up to 8 hours daily, you should not use a computer again when you get home…you should take a break and try to squeeze in some exercise until you go back to work.

6. Stress Disorders

• Technology impacts our behaviors and emotions.
• Prolonged use of computers may be accompanied by poor health and increased pressure placed on you in your workplace environment, which could both lead to stress.
• The longer your stress occurs and is left untreated, the greater your chances are of contracting more serious health problems.
• Stress can lead to decreased attention span, lack of concentration, dizziness and becoming easily burned out.

Tips to Consider

• Promote your own health and prevent future health conditions or worsening the ones you already have by seeking treatment options for any stress that you may encounter.
• Try things from yoga, to natural remedies, to medications as prescribed by a medical provider to combat your stress.

7. Laptop Use Injuries

• Laptop injuries fall into a category of their own; there is a growing use of laptops that continues to cause more pain and strain among those individuals who use them.
• Laptops are designed for short periods of use for those who do not have access to desktop computer.
• In present day individuals choose to use laptops over desktops more frequently, due to convenience.
• The problem is this: the screen and keyboard are very close together and there is really no right way to use a laptop because if you position the screen at the right height for your back and neck, it will cause you to have to lift your arms and shoulders too high to use it and vice versa…no matter what it will probably cause a problem for you somewhere.

Tips to Consider

• Use a desktop computer that is set up ergonomically-correct for you as frequently as possible; only use a laptop intermittently.
• Use separate laptop equipment, such as a wireless mouse or keyboard or a laptop stand.
• As always, take frequent breaks.
• If you have to take your laptop with you, make sure to carry it in a backpack or luggage; otherwise it may cause extra strain on your muscles from carrying it.

8. Sleeping Problems

• Artificial lighting that is given off from computer screens can actually trick your brain and suppress its release of melatonin – the substance that assists your sleeping patterns.

Tips to Consider

• Refrain from using a computer right before going to bed.
• Resort to reading a book or something to that degree prior to going to bed, so falling asleep may come more easily for you.

9. Hearing Loss From Headphones

• At times you may be required to use headphones in order to better concentrate on something or maybe because the background noise level is too high.
• Frequently individuals will turn the volume up very high, when actually it would not even need to be close to that volume to hear the audio effectively.
• Listening to audio with headphones on a consistent basis and using a volume that is too high can result in hearing impairment.

Tips to Consider

• Keep the volume of your headphones down to a tolerable level, one that blocks out any extra noise but that is just loud enough for you to hear.
• Listening to your headphones at approximately 80 decibels is recommended; if you are unaware of what that sound level is it can easily be researched.

10. Increased Risk of Blood Clots

• Being immobile and not allowing your blood a chance to get moving around your extremities may cause it to pool, creating build-up of blood cells that will eventually clot (or stick together) due to not being able to be circulated around.
• Blood clots can be life-threatening if they break away from where they are lodged and travel to another area, such as your lungs.

• Sitting in one position for too long (especially if your legs are crossed), generally over a period of over 4 hours, can greatly increase your risk for this.

Tips to Consider

• Avoid crossing your legs when using a computer for an extended period of time.
• Take many breaks and stretch your legs to get the blood flowing to decrease the chance of it pooling in your extremities.
• If you do have to sit for an extended period, make sure to bend and move your extremities even while sitting because any little bit will help.

Ultimately, it may sound as if using the computer is a bad thing…but most of us really cannot afford to avoid it regardless. Technology seems to be everywhere we turn and soon it will be impossible to go without. As with anything else, using computers is not a bad thing if used responsibly and as directed. Take the advice as mentioned above to your benefit and you’ll be on your way to greatly reducing any risks to your health that may accompany using your computer.

Reference:

• ergonomics.ucla.edu -- UCLA Ergonomics
• Top 10 Computer Related Health Problems - MicroHealth (microhealthllc.com)

When most of us were children mobile phones didn’t even exist, so it can feel quite alien to us when our children feel the need to have one. The ever growing market has tapped into the technology-thirsty young generation and there are even mobile phones for four year olds!

As a parent ask yourself whether your child really needs a mobile phone, and whether you feel they would be capable of using one in an emergency. If you are getting a phone, pick one you feel your child can manage.[1]

Energy-saving LED technology has been in the limelight as the best way to reduce the electricity demands of residential and commercial lighting.But how safe are LED lights? A vision researcher from Complutense University in Madrid reports that exposure to LED lights can cause irreparable damage to the retinas of the human eye, UPI reports.The light from LEDs, or light-emitting diodes, comes primarily from the short-wave, high-energy blue and violet end of the visible light spectrum, said Dr. Celia Sánchez-Ramos. And prolonged, continuous exposure to this light — from computer monitors, mobile phones and television screens or indoor and outdoor lights — may be enough to damage retinas, she said.[2]

Because they emit HEV light (also called blue light), staring at phone and tablet screens may actually harm our eyes permanently. HEV light is that portion of the visible light spectrum that comprises light with the shortest wavelengths, which carry the greatest potential to damage living tissue.

We’re spending almost as much time staring at screens as we do sleeping.
“Many eye care providers are concerned about the potentially damaging effects of high-energy visible (HEV) light emitted by digital devices because laboratory and animal studies have shown exposure to high levels of HEV light can damage tissue in the retina of the eye in a way that appears consistent with retinal changes associated with macular degeneration, a leading cause of permanent vision loss in older adults.” says Dr. Heiting. “But no one knows for sure at this point if prolonged use of digital devices causes sufficient exposure to HEV light to cause permanent eye damage.”

Blue (HEV) light is also emitted by the sun and LED light bulbs, but most of us don’t stare at them for hours on end.[3] eResearch by Navid Ajamin -- spring 2016

Sources of blue light include the sun, digital screens (TVs, computers, laptops, smart phones and tablets), electronic devices, and fluorescent and LED lighting

Blue light is actually everywhere. When outside, light from the sun travels through the atmosphere. The shorter, high energy blue wavelengths collide with the air molecules causing blue light to scatter everywhere. This is what makes the sky look blue. In its natural form, your body uses blue light from the sun to regulate your natural sleep and wake cycles. This is known as your circadian rhythm. Blue light also helps boost alertness, heighten reaction times, elevate moods, and increase the feeling of well being. Artificial sources of blue light include electronic devices such as cell phones and laptop computers, as well as energy-efficient fluorescent bulbs and LED lights. [4]

Bad Impacts of Cell Phone For Small Kids -- sandeeppooni.com

1. Weak Gripping: According to a study in the UK, the kid has a weak grip of the pencil due to the mobile touch screen.

2. Weak Eyes-Sight: The mobile phone has a worse effect on the child’s eyes. Actually, mobile radiation and the screen can damage a lot.

3. Hamper Brain Development: The brain of a child is developing at a rapid pace up to 5 years and it grows up to 18 years.

4. Less Social and Loneliness: The Wireless Telephone addicted children are less social as well as they have the habit to remain alone.

5. Weak Memory: Many studies show that radiation of cell phones also affect the memory of children. Mobile radiation can disturb the memory neurons in the brain.

6. Aggressiveness: The children love to play action games on mobile phones. These action games have lots of violence which affects the soft hearts of children. Therefore, Children who are playing actions games are more aggressive than normal pupils.

7. Digital Zombies: Online gaming is making children digital zombies. In China, the teenager/children use diapers so that they did not want to move away from gaming because if they move then they lose game or gaming points.

8. Poor Sleep: Bedtime usage of phones affects sleep duration as well as the quality of sleep.

9. Poor Grades: The children who have overuse of cell phones have weak school performance. Because they lose their interest in the study and they love to play games or watch others stuff on mobile phones.

10. Nomophobia: This is a fear which founds in phone additive children. In it, the child has a fear of being without its mobile phone or being unable to use its mobile phone for any reason such as poor signal, etc.

11. Neck Problem: This is another common problem in mobile addictive pupils. Due to overuse, the children always feel pain in their neck.

12. Poor Body Posture: The children use the phone for an hour by wrong sitting posture or lying posture which damages the overall body posture of children.

13. Super Hero Addiction/ Virtual World: Children watch excessively superhero cartoon on mobile/tv. So, they want to become like them but, the superhero is virtual.

Smart phones, laptops, and other handheld devices all transmit light. However, the blue light in particular may be toxic for your eyes.

Scientists at the University of Toledo may have discovered how blue light emitted from your technology has a potential to lead to macular degeneration — one of the leading causes of vision loss in the United States.

“It’s no secret that blue light harms our vision by damaging the eye’s retina” said Ajith Karunarathne, PhD, assistant professor at the University of Toledo’s department of chemistry and biochemistry in a released statement.

Macular degeneration is the result of photoreceptor cell death in the retina.

The function of the photoreceptor cells is to capture visual images and signal them to the brain using a molecule called retinal.

Small text and bright screens can strain mobile phone users’ eyes. Since tablet computers, smartphones, and other hand-held devices are designed for reading at close range, users’ eyes must constantly refocus and reposition to process the graphics and text on screen.

Study Cell Phone Radiation Can Damage Eyes Cause Early Cataracts. The scientists, who have studied the impact of electromagnetic waves on human eye, say that cell phone usage can also lead to early cataract in lens apart from affecting retina, cornea and other ocular systems of the eye.

According to The Vision Counci, more than a third of U.S. adults reported spending four to six hours a day with digital media or related electronic devices. As digital use increases, so do potential vision problems, including eye strain.

Symptoms of digital eye strain include eye redness or irritation, dry eyes, blurred vision, back pain, neck pain, and headaches.

Some of the ways to prevent digital eye strain include reducing glare, cleaning the screen, dimming the surrounding lighting that is competing with the device’s screen, keeping adequate distance between eyes and the screen, and increasing text size. Device users are also advised to take breaks from looking at the screen, and follow the “20-20-20” rule:

Take a 20-second break every 20 minutes using an electronic device and look at something 20 feet away.[5]

Mobile manners are passed down and although they should be dictated by common sense, daily instances of egregious tech etiquette seem to indicate otherwise.

Here are a few suggestions on how to set the right example:

• Don’t allow gadgets at the table. At any meal.

• Put your kids before your gadgets and really listen when they are speaking instead of just nodding and saying “uh huh” while looking down at your phone.

• The next time you want to use a gadget to distract them, act as if you don’t have it and see what other tactic you can come up with.

• Relax those dilated pupils and make eye contact with your kids.

• Keep your phone out of clear sight when driving. Sing along to the kids’ music with them instead.

• When someone around you is demonstrating poor mobile manners, subtly point it out to your kids on what not to do.

• Reinforce the age-old “if you don’t have anything nice to say, don’t say anything at all.” This applies to all situations, offline and online.

• Ignore calls when in public places like restaurants or libraries, even in loud, crazy indoor play spaces where you’d love a break for a few minutes.

• Instead of emailing grandma and grandpa, call them.

• Show them that you’re not reliant on your phone 24/7. Have one gadget-free day every week.[6]

Which is more harmful for eyes laptop or mobile?

Though both are harmful as they both cause strain on your eyes since you look at both from a very small distance and they both emit a lot of light. But Mobiles create more of a strain to your eyes as they are smaller devices making it harder for your eyes to catch on that small text.

Reference:

1. familylives.org.uk
2. livescience.com
3. digitaltrends.com
4. bluelightexposed.com
5. source.southuniversity.edu
6. huffingtonpost.com
7. rfsafe.com
8. healthline.com
9. sandeeppooni.com

See also:

• List of countries by number of mobile phones in use
• Blue light and Blue light control lenses -- nicetoview.blogfa.com
• A Parents' Guide to Mobile Phones - ConnectSafely

Headache is one of the most common ailments. But not all headaches are the same — the location of the pain, how severe it is, how long it lasts and how often it occurs, and sometimes what brings on the pain, are some of the variables that doctors use to define different types of headache.

Knowing what type of headache you have can help you and your doctor to manage and treat your headaches.

There are several types of headaches, some common and some complex, resulting in many types of treatments; but for those working specificially with computers may experience a computer eye strain headache. An Eye strain headache is a common type of tension headache.[1]

eye·strain n. Pain and fatigue of the eyes, often accompanied by headache, resulting from prolonged use of the eyes, uncorrected defects of vision, or an imbalance of the eye muscles.

eyestrain n (Medicine / Pathology) fatigue or irritation of the eyes, resulting from excessive use, as from prolonged reading of small print, or uncorrected defects of vision [4]

Symptoms of Eye Strain

1. Headaches
2. Double vision
3. Tired or sore eyes
4. Dry eyes
5. Watery eyes
6. Itchy eyes
7. Burning eyes (even when closed)
8. Heaviness of the eyelids/forehead
9. Fatigue
10. Reading problems
11. Lack of concentration
12. Back/neck aches
13. Spasms/twitches around the eyes
14. Dizziness
15. Lightheadedness
16. Car sickness
17. Nausea
18. Blurred vision [2]

Tension headaches are by far the most common type of headache. Estimates are that from 70 to 90% of all headaches are tension headaches resulting from muscle spasms in the neck and skull. Common causes like eye strain, muscle fatigue, poor posture, overwork, and stress can bring them on. Anything that can help the body to relax can help relieve the pain such as rest, massage, especially to the skull, neck and shoulders, and exercise. We have developed headache relief exercises for the eyes, using a device specifically designed for the relief from a tension headaches that occur when doing near work such as reading and using the computer.

If you still get headaches after using the eye exercises for a few weeks, the cause may be from one of the following: eResearch by Navid Ajamin -- spring 2013

1. Hormonal headaches that revolve around the menstrual cycle. Since homones induce the pain response, mens headaches can be prompted by hormones as well.

2. Vascular headaches such as migraines afflict up to 29.5 million people. Women get 3 times as many migraines than men so hormones may be involved here as well. It is probably tension that causes a constriction of the blood vessel in the brain that produces the visual effect or aura. Shortly thereafter it is replaced with a very severe headache as the involved blood vessel overly dilates to provide increase blood flow to the affected area. Some get physically sick from the severe pain, which is why they have been called sick headaches. There is most likely a genetic component since 4 out of 5 afflicted report family members also get them.

3. Cluster headaches have been described as the most painful of all headaches. They last around 1/2 hour but may reoccur multiple times during the day. Around 5 times as many men as women suffer this type of pain. Fortunately less than 1% of the population get them.

4. Sinus headaches occur when the sinuses get inflammed either from an allergy, an infection or a growth.

5. Organic headaches result in less than 5 % of the cases and are caused from an abnormality in the brain or skull such as a tumor, infection, hemorrhage, aneurysm, hematoma, meningitis, brain abcess or encephallitis.

Remember a headache while at the computer is usually a tension type headache so anything that will help the eye muscles to relax should bring significant relief to an eye strain headache.[3]

If you have visual problems that have not been addressed by prescription glasses or contact lenses, you can get an eye strain headache, which typically causes pain and a heavy feeling around the eyes.[1]

Reference:

1.mydr.com.au 2.ergonomics.about.com 3.computervisionreadingeyeglasses.com 4.thefreedictionary.com/eyestrain

Eye strain or eye fatigue is a common and annoying condition. The symptoms include tired, itching, and burning eyes.Eye strain is rarely a serious condition. Common sense precautions at home, work and outdoors may help prevent or reduce eye fatigue.

Too much screen time puts children at risk for a variety of health issues.

These include:

• Poor sleep quality
• Poor school performance
• Cognitive delays
• Higher risk of obesity
• Delayed social development

The way the eye and its features work is both very quick and automated. The oculomotor muscles are amongst the fastest of the organism and the coordination functions of sight or of its adjustment are almost independant from will.

It is though striking to notice that sleep disorders are never mentioned in front of neurodystonic troubles affecting the eyes.

Migraines and headaches often give cause to a visit to an ophtalmologist and it is often the occasion to detect a more or less severe sight disorder.
The increase of the weekly time spent in front of screens or under artificial lights is often insisted upon without that it is really possible to estimate its true impact : there exist «video game junkies» who spend hours in front of screens without suffering from ocular fatigue or migraine (as far as they get a minimum amount of sleep).
There exist billions of people who work, drive, and live without ever wearing glasses and who neither suffer from ocular fatigue nor migraine.

Sometimes eye strain is a sign of an underlying condition that may need medical treatment. If eye fatigue persists despite taking simple precautions, seek medical advice.

This is especially important if your eye fatigue is associated with headaches or with eye problems such as:

• Pain or discomfort

• Double vision

• Significant change in vision

Causes of eye strain

Any activity that requires intense use of the eyes -for a prolonged time or under difficult conditions can cause eye strain.

These include extended periods of:

• Reading

• Writing

• Computer work

• Driving

Exposure to bright light or straining to see in dim light can also cause eye strain.

One of the most common causes of eye strain is staring for long periods at digital devices such as

• Computer screens

• Smartphones

• Video games

This type of eye fatigue or eye strain is sometimes known as computer vision syndrome (CVS). It affects about 50%-90% of computer workers. The problem isn’t limited to working adults. While children are less susceptible to eye strain, those who stare at portable computer games or computers throughout the day can also experience eye problems.

The problem is expected to grow as more people use smartphones and other hand-held digital devices. Research shows that people hold digital devices closer to their eyes than they hold books and newspapers. That forces their eyes to work harder than usual as they strain to focus on tiny font sizes. eResearch by Navid Ajamin -- summer 2012

Digital devices may also be linked to eye strain because of a tendency to blink less often when staring at a computer screen. People usually blink about 18 times a minute. This naturally refreshes the eyes. But studies suggest that people only blink about half as often while using a computer or other digital device. This can result in dry, tired, itching and burning eyes.

Symptoms of eye strain

Eye strain is associated with uncomfortable and annoying symptoms, such as:

• Sore or irritated eyes

• Difficulty focusing

• Dry or watery eyes

• Blurred or double vision

• Increased sensitivity to light

• Headache or brow-ache

It may be accompanied by pain in the neck, shoulders or back due to holding a bad posture for a prolonged period.

These symptoms can decrease your productivity. They may be intensified by sleep deprivation. During sleep, the eyes are replenished with essential nutrients. Lack of sleep may result in persistent eye irritation.

Common causes of eyestrain include:

• Looking at digital device screens
• Reading without pausing to rest your eyes
• Driving long distances and doing other activities involving extended focus
• Being exposed to bright light or glare
• Straining to see in very dim light
• Having an underlying eye problem, such as dry eyes or uncorrected vision (refractive error)
• Being stressed or fatigued
• Being exposed to dry moving air from a fan, heating or air-conditioning system

Computer and digital device use

Extended use of computers and other digital devices is one of the most common causes of eyestrain. The American Optometric Association calls this computer vision syndrome, or digital eyestrain. People who look at screens two or more hours in a row every day have the greatest risk of this condition.

Computer use strains eyes more than reading print material because people tend to:

• Blink less while using computers (blinking is key to moistening the eyes)
• View digital screens at less than ideal distances or angles
• Use devices that have glare or reflection
• Use devices with poor contrast between the text and the background

In some cases, an underlying eye problem, such as eye muscle imbalance or uncorrected vision, can cause or worsen computer eyestrain.

Some other factors that can make the condition worse include:

• Glare on your screen
• Poor posture
• Setup of your computer workstation
• Circulating air, such as from air conditioning or a nearby fan

Complications

Eyestrain doesn't have serious or long-term consequences, but it can be aggravating and unpleasant. It can make you tired and reduce your ability to concentrate.

How to heal strained eyes?

1. Resting the eyes.
2. Changing the work environment to reduce reflections, glare and bright lighting, and increasing the room's humidity.
3. Adjust your monitor. Position your monitor directly in front of you about an arm's length away so that the top of the screen is at or just below eye level. It also helps to have a chair you can adjust.
4. Adjust your screen settings. Enlarge the type for easier reading. And adjust the contrast and brightness to a level that's comfortable for you.
5. Wearing the proper prescription glasses or adjusting the font. Large-frame glasses cut down on air movement across the corneal surface and help prevent drying.
6. Close your eyes for 30-60 seconds, then follow with a slow blink set. Pair this with the 20-20-20 rule and a quick posture reset to reduce strain quickly.
7. The 30 x 30 x 30 Rule: Every 30 minutes, look away from the screen for 30 seconds and focus on something at least 30 feet away. This technique helps keep the eyes moisturized and resets your focusing system.

Reference:

• blackandlizars.com
• sommeil-mg.net/spip/Ocular-fatigue
• webmd.boots.com/eye-health/eye-strain
• mayoclinic.org/diseases-conditions/eyestrain
• islandeyecare.ns.ca/10-tips-to-protect-your-child-from-digital-eye-strain

Many people spend a large amount of time in the office just dealing with computers. It is not few to see white-collar workers to have all kinds of problems relating to eyes. Maybe they just use their eyes too often. But that is really unjustified. Everybody uses their eyes everyday and no less often than the white-collar workers. The problem lies in the computer screen. Many people say the LCD has less radiation, but the problem is the radiation is always there. In order to solve the problem, a lot of methods have been tried, such as place a plant near our computer, but the result is not satisfactory. Actually, wearing computer glasses is the best and easiest way to fight against computer radiation. There might still be some left, but very little. Many people are against the idea that computer glasses can absorb computer radiation. Many of their ideas are unfounded. Here let’s review something that is of vital importance relating to computer glasses. eResearch by Navid Ajamin -- winter 2012

Why Are Computer Glasses Lenses Anti-radioactive?

Essentially, computer glasses lenses are totally different from general prescription glasses in the way that the lenses are designed. The lenses have been coated with anti-radioactive coatings that have been added with some compound medium. Computer radiation comes from electromagnetic wave that has certain wavelength and amplitude. The working of anti-radioactive coatings has been based on the working theory of the electromagnetic wave, which the amplitude (if two amplitudes are the same) will be strengthened when the wavelength is the same and offset when the wavelength is opposite. Based on this theory, the computer glasses lenses have been coated with many anti-radioactive coatings to generate electromagnetic waves that are of different wavelength to intervene one and another and thus reduce computer radiation.[1]

If you work at a computer for a significant amount of time each day, you may benefit from a pair of special reading glasses known as computer glasses. Even though you wear glasses or contacts on a daily basis, they are probably not quite right for your work at the computer. Computer glasses are special glasses prescribed to lessen the symptoms associated with computer vision syndrome (CVS). CVS describes a group of symptoms caused by prolonged computer use. Symptoms appear because the eyes and brain react differently to words on a computer screen than they do to printed text. Symptoms often include eyestrain, dry eyes, headaches and blurred vision. Many people try to compensate for these vision problems by leaning forward or by looking down to see through the bottom portion of their glasses, often resulting in back and shoulder pain.
Symptoms of CVS can also be caused by presbyopia, a vision disorder that develops as we age. Presbyopia is the loss of the eye's ability to change focus to see near objects, and usually becomes noticeable around the age of 40. If you think you might be feeling some of the symptoms of CVS, you may need to purchase a pair of computer glasses. Computer glasses are prescription glasses specially designed to allow patients to work comfortably at a computer. Computer work involves focusing the eyes at a close distance. Because computer monitors are usually placed a little further away than a comfortable reading distance, standard reading glasses are usually not enough to alleviate symptoms of CVS. With computer glasses, the whole lens focuses at the same distance and does not require you to tilt your head back to see the computer screen.[2]

"Children are vulnerable because they have large pupils and pristine lenses," said Barnes. "The American Academy of Pediatrics states that no child under the age of two years should be on any computer device. And I would extend the limitation to children five years of age."

Blue light is emitted by computer screens, laptops, notebooks, tablets, smart phones, LED lights and television screens.

Blue light is the shorter wavelength of light called High-Energy Violet light or HEV. The most damaging HEV Wavelength is between 400 and 420 nanometers (nm). This is the most harmful wavelength to the retina, causing macular degeneration or macular re-modulation.

Computer glasses for kids are specially designed to block blue light from digital devices. Giving your children blue light blocker glasses will virtually eliminate the effects of digital eye strain and significantly reduce the risk of AMD and other retinal degenerative diseases.

Blue light has been linked to all sorts of issues, from causing digital eye strain to making us blind. There's a lot of conflicting evidence, however, about exactly how harmful (or not) it really is.During daylight, blue wavelengths of light can be beneficial, playing an important role in setting circadian rhythms, boosting attention and mood. But we didn’t evolve to be exposed to it as much as we are. In addition to the ample blue light in sunlight, most of the light we are exposed to via digital devices is also blue. For example, the most common type of LED used in electronic devices is a white-light LED, which actually has a peak emission in the blue wavelength range (400 – 490 nm). Moreover, the eye’s cornea and lens are unable to block or reflect blue light.

Increasing evidence suggests that blue light has a dark side. At night, it can suppress the secretion of melatonin and wreak havoc on our circadian rhythms, and recent studies have shown that extended exposure to blue light can damage the retina, though exactly how it does this has not been clear.

Now, new research from the University of Toledo demonstrates that when blue light hits a molecule called retinal, it triggers a cascade of chemical reactions that could be toxic to cells in the retina of the eye.

Reference:

• buyeyeglasses.pythonblogs.com
• vision.about.com
• globenewswire.com
• forbes.com

People who spend more than two hours on a computer each day will experience symptoms of CVS or Computer Vision Syndrome.

The most common symptoms include

• dry eyes
• tired eyes
• headaches
• aching eyes
• burning eyes
• double vision
• blurred vision
• light sensitivity
• general eyestrain
• focusing difficulties
• neck and shoulder pain

Suggestions That Can Help Reduce Some of the Effects of CVS

• Glare screen filters may be helpful for some people, but they will not solve your computer  problems because they only affect glare from the computer screen, not the problems caused by the constant refocusing the eyes must do when working on a computer. An anti-reflective coating (AR Coat) on the lenses of glasses will reduce the glare coming at you and from behind you that causes eyestrain.            

• Proper lighting can reduce eyestrain and glare. Glare is created by glare on walls and other surfaces, reflections from the computer screen, bright light coming in from outside, and bright light inside. To decrease light and reflections from external light, close drapes or blinds. When using computers, lighting should be about half of that used in most offices. Using fewer light bulbs or florescent bulbs or use lower intensity bulbs can reduce glare caused by overhead lighting.

• Take a 10-15 minute break every hour to reduce eyestrain. Look away from the computer screen every 10-15 minutes and focus for 5-10 seconds on a distant object outside or down the hallway or get up and take a short walk. Everyone tends to stare at the computer and blink less, about 5 times less than normal, according to studies. Staring and decreased blinking dry the eyes out. Taking frequent breaks allows normal blinking and better wetting of the eyes. Office buildings tend to be dry environments that also reduce tearing. If you are experiencing significant dryness, ask your eye doctor about artificial tears or eye drops that you can use during the day. By modifying your work area, you can reduce eyestrain and other effects of CVS. If you need to look back and forth between the printed or written page and the computer, eyestrain can occur. Place written pages on a copy stand next to the monitor. Properly light the copy stand. Adjust your workstation and chair to the correct height. Purchase ergonomic furniture to assure proper screen locations and posture. Poor ergonomic setup is a cause of head, neck, shoulder, and back pain.

• Place your monitor directly in front of you, not off to one side. It should be about 20 to 26 inches away from you. Make sure your monitor is just right for you, not too high and not too low. You may need to raise or lower your chair. If you reposition your chair, keep in mind that your arms should be parallel to the floor when you type, and your feet should be flat on the floor or on a footstool. Finally, maintain good posture at your desk: keep your back straight and your shoulders back. Adjust the contrast between the background and the characters on the screen by adjusting the brightness on your computer screen.[1]

Hitzeman recommends looking away from the computer screen for a minute or two several times per hour.

Additionally, he says there are many other risks associated with using a computer monitor for long periods of time, but each one can be helped with these tips:

1. Blink. It may sound strange, but remembering to blink is important. According to Hitzeman, when someone stares at one object for a long time, they don't blink. This can lead to dry eyes, which can in turn lead to corneal irritation and diseases. People who have dry eyes naturally are especially at risk of chronic dry eye, which weakens the corneal structure.
2. Position your monitor correctly. Besides making sure your monitor is about two feet away and four inches below eye level to minimize neck strain, Hitzeman recommends making sure your monitor is glare-free. Any glare on the screen makes it harder to focus, which causes additional stress on the eye.
3. Get computer glasses. Just like reading glasses, those extremists who look at a monitor eight hours a day should consider getting computer glasses. These are specially designed to make it as easy as possible for your eyes to focus on the computer screen. According to Hitzeman, the optometrists will test your eyes while you look at a monitor, giving the ideal computer screen prescription.
4. Get regular eye exams. According to the American Optometric Association, adults should get their vision checked once at least every two years. This is especially important to computer vision syndrome, because improperly corrected vision can lead to the syndrome more easily, and even can cause permanent ocular damage. "Other than the dry eye issues, the only other damage that can occur from working excessive hours with a computer monitor comes from improperly corrected vision," said Hitzeman. "Everything else is just fatigue and can be fixed with rest." [2]

There is a difference in visual demand when one is viewing the display on the computer screen compare to reading a printed text. An image which is produced on the screen is made up of thousands of tiny spots or pixels and rasters which collectively form the image. The margin of the image or a word is usually not sharp and this is worsening if the image or word is formed by minimal pixels, or what is known as low resolution. As the resolution goes down the image become poor in quality and the visual demand of a reader has to be increased in order to appreciate well the wording or image. The contrast (intensity of the light) of the word to the background, the glare of the computer screen and the reflection from the glass screen are all important factors determining the amount of visual demand one must put in order to perceive the image well.[3]

Reference:

1. mdsupport.org/library/cvs.html 
2. newsinfo.iu.edu/news/page/normal/10479.html
3. ncbi.nlm.nih.gov/pmc/articles/PMC4170366

What Are Computer Eye Strain Glasses Anyway?
They are glasses specially designed to mitigate the effects of the digital world we are all now part of, aka digital eyewear.

Why Does a Child With Perfect Vision Need Glasses For Computer Work?

Because the digital world is different and puts different requirements on our eyes. Pixels are different to print - they are bright in the center and fade towards the edges whereas print is a solid experience. Pixels require a different way of focusing that our eyes are not used to yet and experience as a strain - a computer eye strain. Glasses can help lessen this strain.

Likewise, our range of sight is categorized into a Near vision zone (14 to 16 inches from your eyes), Intermediate vision zone (arms length, 20 to 24 inches from your eyes), and Distance zone. Digital interaction happens primarily in the Intermediate vision zone and requires the eyes to remain fixed in focus. Both the use of this vision zone and the requirement to fix focus are new demands for our eyes and as such are experienced as strains.

Parents need to be aware of the vision challenges associated with computer work. For younger children computer use, which means any digital tool, requires fine motor skills that are not yet well developed. Only when their visual system matures will the child be better able to handle the stresses of digital life.

The focal point for children's sight is in the Near vision zone. Digital screens are usually in the Intermediate vision zone. Many young people can compensate without significant issues in the short term. But, there is some evidence that the constant effort to focus can induce so called "accommodative spasms" which may lead to increased or premature myopia - short-sightedness, according to the Macular Degeneration Society. Other young people, who have focusing and binocular problems, uncorrected hyperopia (farsightedness), or uncorrected astigmatism, experience significant symptoms of computer eyestrain.

By wearing computer eye strain glasses that are set up for computer-working-distance and that decrease the accommodative effort needed to focus on the digital screen, permanent vision changes can be prevented. Even contact lens wearers may need to wear glasses over their contacts for computer use to prevent these side-effects.

The Canadian Center for Occupational Health & Safety says "wearing specially prescribed computer glasses when working at your computer may keep your eyes from getting worse by reducing excessive focusing demands on your eyes. This is particularly true for teenagers, whose eyes may be more susceptible to progressive nearsightedness from focusing fatigue".

Computer work involves focusing the eyes at close distances. Because of space constraints or lack of solid information on how the eyes function computer monitors are often placed in positions that exacerbate the already increased ocular requirements. Therefore, by wearing special glasses that decrease the accommodative effort young people can prevent premature vision changes (deterioration).

For computer users, there are special types of lenses. And, they are not meant for other purposes like driving or regular purpose.

These lenses are available in the anti-glare coating that is even betterfor computer users.

- Single Vision Lenses: Basic eyeglasses for computer protection feature single vision lenses having a modified lens power. It offers the largerst field of view to the wearer and eases the amount of accommodation needed to keep things in focus at the distance of the computer screen.
Using single vision computer eyeglasses can lower the risk of:
Blurred vision, Eye strain and Unnatural posture that can lead to problems like a backache and neck pain.

- Occupational Progressive Lens: A multipurpose lens with no visible lines as in a traditional bifocal.
It corrects all types of vision- near, intermediate and distant. It is different from a regular progressive lens as it features a larger intermediate zone, which provides you a better and comfortable vision, while you are working on the computer. Hence, they are not recommended for tasks involving distance objects.

- Occupational Bifocal and Trifocal Lenses: These have a larger zone for near vision as well as for intermediate vision.

Reference:

• ezinearticles.com
• coolwinks.com/blog/best-eyeglasses-to-help-you-deal-with-computer-eye-strain

See also: Are Photochromic Lenses As Good As Computer Glasses?

Read short messages or surfing the Internet through a smartphone tend to force people’s eyes to work harder than when reading books or newspapers. A study involving 130 volunteers, with an average age of 23.3 years old, studied how people hold the phone while reading a short message. Then, another 100 volunteers, with an average age of 24.9 years old were studied while they read the pages.

When we read newspapers, books, or printed magazines, the average distance to the eye is 40.64 centimeters. Apparently in average, people who read or send short messages is only 35.56 centimeters. eResearch by Navid Ajamin -- spring 2010

In some people, it is even closer about 17.78 centimeters. The research was done by a team from ‘SUNY State College of Optometry’ in New York City, the study states that the additional burden would cause complaints such as headaches, dry eyes, discomfort, myopic, and tension in the eyes. The results are published in the Optometry and Vision Science journal in July 2011.[1]

Computers and digital devices have certainly transformed the way the average worker completes their daily tasks, but they also pose a hidden danger to our eyes, one that many digital device users are simply unaware of. With so much time being spent in front of computerized screens--be it in front of the laptop or the iPhone--device users are increasingly suffering at the hands of what eye care professionals call Computer Vision Syndrome.

New research out from the firm VSP Vision Care shows that a big chunk of eye care patients today complain of the common symptoms attached to the syndrome. "Computer Vision Syndrome is a major problem for Americans," said Dr. Nate Bonilla-Warford, an eye doctor and a VSP provider. “We are seeing patients uncomfortable in the workplace with neck pain, headaches, eye strain, blurred vision, etc. that could easily be avoided.

It's important for people to discuss their digital usage with their eye doctor and make sure they are getting annual eye exams." Channel Insider takes a look at the study's findings and three important ways that doctors such as Bonilla-Warford recommend to prevent your screens from killing your vision.[2]

What happens if you spend hours on your phone?

Negative Effects of Too Much Screen Time:

Eye Strain and Headaches - Too much time spent looking at screens can cause fatigue or discomfort in your eyes as well as dimmed vision. Glare on screens and the brightness of the display can place further strain on your eyes. Eventually, this strain can lead to headaches.[3]

Reference:

1. medicmagic.net
2. channelinsider.com
3. reidhealth.org/blog/screen-time-for-adults

If you work at a computer for a significant amount of time each day, you may benefit from a pair of special reading glasses known as computer glasses. Even though you wear glasses or contacts on a daily basis, they are probably not quite right for your work at the computer.

People who spend more than two hours on a computer each day will experience symptoms
of CVS or Computer Vision Syndrome.

The most common symptoms include :

headaches, focusing difficulties, burning eyes, tired eyes, general eyestrain, aching eyes, dry eyes, double vision, blurred vision, light sensitivity, and neck and shoulder pain.

Computer glasses are special glasses prescribed to lessen the symptoms associated with computer vision syndrome (CVS). CVS describes a group of symptoms caused by prolonged computer use. Symptoms appear because the eyes and brain react differently to words on a computer screen than they do to printed text. Symptoms often include eyestrain, dry eyes, headaches and blurred vision. Many people try to compensate for these vision problems by leaning forward or by looking down to see through the bottom portion of their glasses, often resulting in back and shoulder pain.

Symptoms of CVS can also be caused by presbyopia, a vision disorder that develops as we age. Presbyopia is the loss of the eye's ability to change focus to see near objects, and usually becomes noticeable around the age of 40. If you think you might be feeling some of the symptoms of CVS, you may need to purchase a pair of computer glasses. Computer glasses are prescription glasses specially designed to allow patients to work comfortably at a computer. Computer work involves focusing the eyes at a close distance.

Because computer monitors are usually placed a little further away than a comfortable reading distance, standard reading glasses are usually not enough to alleviate symptoms of CVS. With computer glasses, the whole lens focuses at the same distance and does not require you to tilt your head back to see the computer screen.

An optometrist or ophthalmologist will be able to prescribe a pair of computer glasses that will elp to relieve symptoms brought on by CVS. Before your appointment, however, take a good look at your work space. It is important to tell your doctor exactly how your work space is set up, including the distance between your monitor and your eyes, in order to prescribe the appropriate computer glasses. Also, pay attention to lighting. Bright lights are often a source of eyestrain in the office. Anti-reflective (AR) coatings may be applied to your lenses to reduce the amount of glare and reflected light that reach your eyes. The following lenses are designed specifically for computer use: eResearch by Navid Ajamin -- summer 2012

• Single Vision: Single vision lenses are the simplest type of computer glasses. The entire lens is designed for seeing the computer monitor, providing the largest field of view. Many people, adults as well as children, enjoy these lenses because the monitor appears clear without obstructions. However, distant objects as well as objects that are closer than the computer screen will appear blurry.

• Flat-top Bifocal: A flat-top bifocal lens looks just like a regular bifocal lens that some people wear for distance and near vision. These lenses are designed so the top half of the lens is set to focus on the computer monitor while the bottom segment is set to focus on closer reading material. These lenses have a visible line that divides the two focusing segments. Even though these lenses provide comfortable viewing of the computer, objects in the distance will appear blurry.

• Variable Focus: Some eye care specialists call this lens a "computer progressive" lens. Although similar to a traditional no-line invisible progressive multifocal lens in design, a variable focus lens is much more task specific. This lens has a small segment at the top part of the lens for viewing objects in the distance, a wide intermediate segment for viewing the computer monitor, and finally a small segment in the lower part of the lens for focusing on close objects. No visible lines or segments are in this type of lens, so it feels more like normal vision.

Computer glasses can benefit computer users as long as they are properly fitted and correctly prescribed. Optometrists and ophthalmologists are knowledgeable in problems resulting from computer vision syndrome and can help you find an appropriate pair.

Reference: vision.about.com mdsupport.org

Visual Fatigue Syndrome (VFS) is caused by focusing on objects, such as computers, that are 1 to 3 feet away for extended periods of time.The symptoms of VFS are not only bothersome, they can also be painful, reduce the enjoyment of your day, and reduce the quality of your work.

Stress impacts us mentally and physically, but did you know it can affect our vision?

When we are severely stressed and anxious, high levels of adrenaline in the body can cause pressure on the eyes, resulting in blurred vision. People with long-term anxiety can suffer from eye strain during the day on a regular basis. If you become highly sensitised to any slight movement, over time the strain from other senses can cause muscular tensions and headaches.

SYMPTOMS OF STRESS-RELATED VISION IMPAIRMENT:

• Tunnel vision. You may lose some of your peripheral vision and feel like you can only see straight in front of you.[4]

• Sensitivity to light and movement; light may hurt your eyes or make it difficult for you concentrate, and focus.
• Eye twitching; eyes can randomly spasm, with no pain but discomfort.
• Very dry or very wet eyes; both can be a symptom, however, can also be caused by other issues.
• Blurry vision; finding it hard to concentrate, or focus. If you have additional symptoms, visit your local GP.
• Eye strain; discomfort and minor pain as your eyes feel tight and swollen.
• Eye floaters; tiny spots that swim across your vision.

If you have any of these symptoms with no other medical issues, the best option for you is to get enough rest, eat healthily, use meditation, or any stress relief exercises that help you to relax. Taking at least a few minutes to consciously relax will help your body calm down.[3]

Risks and consequences of oxidative stress. The eye is an organ that is predisposed to great levels of oxidative stress. The eye is constantly exposed to factors such as radiation, chemicals, oxygen, drugs, which induce the formation of reactive oxygen species (ROS) that can ultimately damage cells. This figure is modified from Flammer J. Glaucoma, Glaucoma A Guide for Patients. An Introduction for Care-Providers. A Quick Reference. 3rd ed. Cambridge: Hogrefe & Huber; 2006. Figure S1.29; p 222.

In recent years there has been a shift in the way we use our vision. Instead of using our eyes to see most things at distance, we spend most of the day viewing objects that are within arms reach. These items include the computer, television, cell phone, PDAs, even books are now available in digital format. Both the real world and written word have now been replaced by a constant barrage of illuminated, digital pixels. This new visual environment commonly induces visual fatigue. eResearch by Navid Ajamin -- spring 2011

Users of digital media may experience eyestrain, blurred vision, tired eyes, dry eyes, neck and back pain. Even those who can see 20/20 and those who do not normally wear glasses may experience visual fatigue. Studies have shown us that 83 percent of all individuals experience one or more symptoms of Visual Fatigue Syndrome.

Unfortunately most of those affected by visual fatigue are not getting the help they need.The reason is poor education. Most people do not understand why they are experiencing problems and, in many cases, eye doctors are not properly trained to recognize the symptoms of visual fatigue. Even when an eye doctor is well informed, he or she may lack the proper tools necessary to help patients combat symptoms.[2]

Driving is a complex task, requiring full concentration and a calm attitude. Heightened emotions such as stress, anger or upset are a form of cognitive distraction that can significantly impede drivers’ ability to spot and respond to hazards. Research has found that drivers who suffer from work-related stress are more likely to speed and take other risks while driving and more like to be involved in serious crashes [5]

Reference:

1. eyewalk.net/innovation/antifatigue_en
2. iowaeyeblog.com/2009/11/visual-fatigue-syndrome
3. whitbyonline.com/about-us/news/stress-on-your-eyes
4. allabouteyes.com/stressed-stress-affects-eyes
5. brake.org.uk/facts-resources/15-facts/487-driver-stress

See Also:

• Anti-Fatigue Lenses
• What are anti-fatique lenses
• Can Stress Cause Blurry Vision?
• Overview Of Anti-Fatigue Lenses

معمولا افرادی که با کامپیوتر زیاد سر وکار دارند در هنگام کار با کامپیوتر بعد از مدتی دچار سوزش ، خستگی ، چشم درد و سردرد میشوند .بنابراین لازم است جهت جلوگیری از ایجاد این مشکلات نکات زیر را رعایت نمایید.

١- رعایت فاصله استاندارد که بهترین فاصله حدود ۴٠ تا ۵٠ سانتیمتری است .

٢- نور محیط بایستی نور کافی و استاندارد باشد استفاده از لامپ های با نور سفید و زرد توام با هم بهترین نور میباشد البته مقدار نور به اندازه ای زیاد نباشد که چشم دچار خیرگی شود .

٣- صفحه مونیتور به شکلی قرار داده شود که نور منبع روشنایی و یا نور محیط بیرون به طور مستقیم به آن نتابد .

۴- مونیتور باید درست در مقابل چشم و در راستای محور بینایی هر دوچشم باشد .

۵- جهت جلوگیری از خشکی چشم تعداد پلک زدن بایستی نسبت به مواقع عادی بیشتر باشد .

۶- از مونیتور های استاندارد که تشعشعات کمتری دارند استفاده شود .

٧- سعی کنید چشمان خود را به مدت طولانی روی صفحه مونیتور خیره نکنید و در هنگامی که نیاز به نگاه کردن به مونیتور ندارید چشم خود را از مونیتور برداشته وبه فاصله های دور تر نگاه کنید .

٨- معمولا بعد از حدود دو ساعت کار با کامپیوتر حدود ١۵ تا ٣٠ دقیقه استراحت نمایید و در این فاصله یک نوشیدنی شیرین و یا یک شیرینی سالم مانند خرما _ بیسکویت یا عسل استفاده کنید .

٩- کنتراست و روشنایی مونیتور را به شکل استاندارد تنظیم نمایید .

١٠- در صورتی که تمامی نکات را به درستی رعایت کردید و باز هم دچار مشکل شدید ممکن است مشکلی در سیستم بینایی شما وجود داشته باشد مثلا چشم شما ضعیف باشد و یا چشمان شما دچار عدم تعادل عضلانی باشد بنابراین بهتر است جهت کنترل سیستم بینایی به متخصص بینایی سنجی و یا چشم پزشک مراجعه نمایید .

١١- افرادی که نمره چشم آنها دوربینی و یا استیگماتیسم است حتما بایستی از عینک استفاده نمایند . افراد نزدیک بین ممکن است در نمرات کم نیازی به استفاده از عینک نداشته باشند و یا در نمرات بالا هم ممکن است به نمره کمتری نیاز داشته باشند بنابراین در این مورد با متخصص خود مشورت نمایید .

What are the symptoms?

Computer vision syndrome symptoms include:

• Eye discomfort (most common). This can feel like dryness, watering, itching, burning or the sensation of something in your eye.
• Blurred vision that comes and goes. You may notice it when refocusing your eyes from near to distance or distance to near.
• Sensitivity to bright lights.
• Trouble keeping your eyes open.
• Headache behind your eyes.

Many people with computer vision syndrome also develop aches and pains elsewhere in their bodies. This can happen when your posture isn’t ideal or you stretch and strain your neck to see your screen. Symptoms can include pain in your:

• Neck.
• Shoulders.
• Back.

What causes computer vision syndrome?

Extensive use of digital devices causes computer vision syndrome. Some research shows that continuous screen use for at least two hours can be enough to trigger symptoms. The longer you spend staring at screens, the more likely you are to develop symptoms.

The screens themselves aren’t fully to blame. Spending a long time focusing on close-up objects can strain your eyes, whether you’re looking at a screen or a printed page. But the screens add another layer of strain to your eyes. Here’s why:

• Constant refocusing. When you use screens, you have to constantly focus and refocus to see the print (which is made of pixels, or tiny dots). Constantly moving your eyes in this way can strain them.
• Screen contrast levels. Often, there’s a low contrast level between the letters you read on a screen and their background. This can make your eyes work harder.
• Inadequate blinking. Normally, you naturally blink about 18 to 22 times per minute. You need to blink enough to keep your eyes lubricated. But when using a computer, most people only blink three to seven times per minute. Screen use may also cause incomplete blinking. This means you only partly close your eye when you blink. Not blinking fully or often enough can cause the surface of your eyes to dry out.

What are the risk factors for this condition?

You face an increased risk of developing computer vision syndrome if you use computers or other digital devices for at least four hours per day.

Your symptoms may be more severe than usual if you:

• Have dry eye disease.
• Have uncorrected or under-corrected refractive errors, like nearsightedness.
• Have eye conditions that affect your eyes’ ability to focus, like convergence insufficiency.

Reference: Computer Vision Syndrome: Symptoms, Treatment & Prevention (clevelandclinic.org)

چشمان شما خسته می شوند. سرتان درد می گیرد. نشسته اید و به صفحه مانیتور کامپیوترتان خیره شده اید. اگر شما یکی از کسانی باشید که برای انجام کارهای حرفه یی و شخصی عادت به استفاده روزانه از کامپیوتر دارند، ممکن است خستگی چشم را تجربه کنید. علائم و نشانه های رایج اینها هستند؛ درد، خستگی، سوزش یا خارش چشم ها، خشکی چشم ها، تاری دید یا دوبینی، سردرد و درد گردن، دشواری در تغییر تمرکز از صفحه نمایشگر به صفحه کاغذ، رویت لبه های رنگی و تصاویر پس از روی گرداندن از صفحه نمایشگر و افزایش حساسیت به نور.

به نظر نمی رسد خستگی چشم به دلیل کار با کامپیوتر عواقب جدی یا طولانی مدت در پی داشته باشد، اما ناخوشایند و مزاحم است. اگرچه شاید شما نتوانید ماهیت شغل تان را تغییر دهید یا تمامی عوامل موثر در ایجاد خستگی را از میان ببرید، اما می توانید در جهت کاهش خستگی قدم هایی بردارید.

● عادات جدید می توانند مفید باشند

چند تغییر ساده در نحوه کاربرد اینترنت می تواند تا حد زیادی نیاز چشمان شما را به استراحت برآورده سازد. برای کاهش خستگی این چند نکته را رعایت کنید؛

▪ به چشمان تان استراحت دهید؛ در طول روز چشمان تان را وادارید که روی چیزی به جز صفحه نمایشگر متمرکز شوند. تمرین زیر را انجام دهید؛ انگشت تان را در فاصله چند سانتیمتری صورت تان نگاه داشته و به آرامی آن را دور کرده و در همین حال به آن خیره شوید. سپس به یک شیء در دوردست خیره شده و به انگشت تان بازگردید. حالا انگشت تان را به آرامی به سوی صورت تان بازگردانید. در این مرحله روی چیزی در فاصله دو و نیم متری چشمان تان متمرکز شده و برای چند ثانیه در همین حال بمانید. این تمرین را روزی چندین مرتبه تکرار کنید.

▪ مکان تان را تغییر دهید؛ تقریباً هر دو ساعت یک بار سعی کنید بایستید و به اطراف حرکت کنید. در صورت امکان ساعتی یک بار به عقب تکیه داده و چشمان تان را برای پنج دقیقه استراحت دهید. طی این مدت به یک کار غیرکامپیوتری بپردازید.

▪ پلک و چشمک بزنید؛ از آنجایی که بسیاری از مردم در زمان کار با کامپیوتر کمتر از میزان لازم پلک می زنند، در صورت طولانی شدن کار به خشکی چشم دچار می شوند. پلک زدن سبب تولید اشک شده و می تواند به نرم و مرطوب شدن چشم ها کمک کند. سعی کنید به صورت آگاهانه بیش از میزان معمول پلک بزنید و در صورتی که این کار کمک کننده نباشد، از اشک مصنوعی که بدون نسخه پزشک به فروش می رسد، استفاده کنید.

▪ چشمان تان را ماساژ مختصری بدهید؛ روزانه چند بار چشمان تان را ماساژ دهید. آرنج هایتان را روی میز بگذارید به طوری که کف دست هایتان رو به بالا باشد. وزن خود را به جلو و روی دستان تان رها کنید. کف دست ها را روی چشمان تان قرار داده و در حالی که انگشتان تان به سمت پیشانی باز شده اند، چشم ها را بسته و با بینی نفس عمیقی بکشید. این کار را برای چهار ثانیه ادامه داده و سپس نفس خود را خارج کنید. این تنفس عمیق را برای ۱۵ الی ۳۰ ثانیه ادامه دهید.

▪ اشک خود را به میزان کافی برسانید؛ اگر از عینک یا لنز تماسی استفاده می کنید، مطمئن شوید انتخاب عینک به درستی انجام شده و برای کار با کامپیوتر مناسب است. بیشتر عدسی های تماسی برای خواندن نوشته های روی کاغذ مناسب اند و ممکن است برای کار با کامپیوتر ساخته نشده باشند. عینک ها یا عدسی های تماسی که به طور اختصاصی برای این کار طراحی شده اند، ممکن است گران قیمت باشند.

▪ محیط کارتان را مرتب کنید؛ فضای میز تحریرتان را به شیوه یی مناسب برای چشمان تان مرتب کرده و به این ترتیب از خستگی چشم هایتان بکاهید.

▪ مانیتور خود را تنظیم کنید؛ صفحه مانیتور را در فاصله ۴۵ تا ۵۰ سانتیمتری چشمان تان قرار دهید. بسیاری از افراد فاصله صفحه مانیتور را در حدود طول یک بازو از چشم هایشان تنظیم می کنند. اگر مجبورید برای خواندن متن های ریز بیش از حد به کامپیوتر نزدیک شوید، باید اندازه حروف را بزرگ تر کنید.

بالای صفحه نمایشگر باید پایین تر از چشم ها یا هم سطح با آن باشد تا بتوانید مستقیماً به کارتان نگاه کنید. اگر صفحه زیادی بالا یا زیادی پایین باشد، می تواند سبب کمردرد شود. اگر مانیتور را در بالای کیس قرار می دهید، باید کیس را روی زمین بگذارید. اگر از عینک دوکانونی یا سه کانونی استفاده می کنید، به خاطر داشته باشید که ممکن است تمایل به خم کردن سر به عقب داشته باشید تا بتوانید از ورای بخش پایینی عینک تان به صفحه مانیتور نگاه کنید. برای تطابق با این شرایط صفحه مانیتور را چند سانتیمتر پایین تر آورده یا از عینک هایی استفاده کنید که برای کار با کامپیوتر ساخته شده باشند.

Computer eye strain: 10 steps for relief

1. Get a comprehensive eye exam.
2. Use proper lighting.
3. Minimize glare.
4. Upgrade your display.
5. Adjust your computer display settings.
6. Blink more often.
7. Exercise your eyes.
8. Take frequent breaks.
9. Modify your workstation.
10. Consider computer glasses.

▪ صفحه کلید را در وضعیت مناسبی قرار دهید؛ صفحه کلید را مستقیماً روبه روی صفحه مانیتور قرار دهید. اگر آن را در یک گوشه قرار دهید، چشمان شما ناچار هستند در فواصل متغیری نسبت به صفحه مانیتور متمرکز شوند و این کاری خسته کننده خواهد بود.

▪ وسایل تان را در نزدیکی خود قرار دهید؛ چیزهای خواندنی و ابزارهای لازم را در یک نگهدارنده در کنار مانیتور و در همان سطح، زاویه و فاصله از چشمان تان قرار دهید که مانیتور قرار دارد. به این ترتیب چشمان شما ناچار نیستند مداوماً تطابق پیدا کنند.

▪ نور را بررسی کرده و از درخشش زیاد بپرهیزید؛ نور خیره کننده می تواند رویت اشیا را روی صفحه مانیتور با دشواری همراه کرده و چشم های شما را خسته کند. برای بررسی میزان درخشندگی در حالی که مانیتور خاموش است در جلوی کامپیوتر بنشینید. این کار به شما امکان می دهد نور انعکاس یافته و تصاویری را ببینید که در حالت عادی نمی بینید. هرگونه درخشش شدید و خیره کننده را مورد توجه قرار دهید. بیشترین مشکلات مربوط به منابع نورانی واقع در بالای سر یا پشت سر شما مثل نور فلوئورسنت و نور خورشید است. در صورت امکان مانیتور خود را به گونه یی تنظیم کنید که نورهای شدید کناره ها تا زاویه ۹۰ درجه یی نسبت به صفحه مانیتور خاموش شوند. توجه داشته باشید که همه نورهای بالای سر یا تمامی آنها را خاموش کنید.

Reference: allaboutvision.com/cvs/irritated.htm

CVS چیست؟ مجموعه ای از علائم چشمی و بینایی است كه بر اثر كار با كامپیوتر ایجاد می شود.تقریباً 3/4 كسانیكه زیاد با كامپیوتر كار می كنند گرفتار این علائم هستند. به نظر می رسد با فراگیرتر شدن بكارگیری كامپیوتر در محل های كار و حتی در خانه ها تعداد كسانیكه ازCVS رنج می برند رو به افزایش باشد.

Computer Vision Syndrome is the name given to eye problems caused by prolonged computer use including: Eye irritation (Dry eyes, itchy eyes, red eyes) Blurred vision. Headaches. Backaches.American Optometric Association (AOA) defines CVS or digital eye strain as a group of eye and vision-related problems that results from prolonged usage of computers, tablets, e-readers, and cell phones which causes increased stress to near vision in particlular. CVS:Computer Vision Syndrome

CVS also has symptoms that cause discomfort to the eyes of children such as dryness or a burning sensation. Excessive use of screens may result in myopia, or near-sightedness, at a younger age than would otherwise be expected. Poor posture while using screens can lead to neck, shoulder, and back strain.

علائم CVS:

مهمترین علائم عبارتند از: خستگی چشم، خشكی چشم، سوزش، اشك ریزش و تاری دید، همچنین ممكن است سبب درد گردن و شانه ها نیز بشود.

چشم انسان حروف چاپی را بهتر از حروف نمایش داده شده بر روی مانیتور می بینند. علت این امر این است كه حروف چاپی كنتراست بیشتری با صفحه سفید زمینه داشته و لبه های آنها واضح تر است حال آنكه در مورد صفحه مانیتور چنین نیست و لبه ها به وضوح حروف چاپی نیستند بلكه حروف از یك مركز با كنتراست بالا شروع شده و به تدریج كم رنگ تر می شوند و پس از تبدیل به خاكستری كمرنگ ناپدید می گردند. بنابراین لبه های حروف بر روی صفحه مانیتور وضوح حروف چاپی را ندارد.

یكی از مهمترین دلایل خشكی و سوزش چشم هنگام كار با كامپیوتر كاهش میزان پلك زدن است بطوریكه افراد هنگام كار با كامپیوتر تقریباً 5/1 حالت عادی پلك می زنند. این مساله به همراه خیره شدن به صفحه مانیتور و تمركز بر روی موضوع كار سبب می شود تا پلك ها مدت بیشتری باز بمانند و در نتیجه اشك روی سطح چشم سریعتر تبخیر می شود.

11 توصیه برای كاهش علائم CVS

1- سعی كنید بطور ارادی پلك بزنید. این كار سبب می شود سطح چشم شما با اشك آغشته شده و خشك نشود.

در صورتیكه مشكل شما شدید باشد می توانید از قطره های اشك مصنوعی استفاده كنید.

2- مركز مانیتور باید حدود 10 تا 20 سانتیمتر پایین تر چشمان شما باشد. این وضعیت علاوه بر اینكه باعث می شود پلك ها پایین تر قرار گیرند و سطح كمتری از چشم در معرض هوا باشد، از خستگی گردن و شانه ها نیز می كاهد. در این موارد هم باید مانیتور را در ارتفاع مناسب قرار داد و هم ارتفاع صندلی را نسبت به میزكار تنظیم كرد بطوریكه ساعد شما هنگام كار با keyboard موازی با سطح زمین باشد.

3- مانیتور خود را طوری قرار دهید كه نور پنجره یا روشنایی اتاق به آن نتابد، هنگام كار با كامپیوتر سعی كنید پرده ها را بكشید و روشنایی اتاق را نیز به نصف وضعیت معمولی كاهش دهید. اگر از چراغ مطالعه بر روی میز خود استفادهمی‌كنید آن را طوری قرار دهید كه به صفحه مانیتور یا چشم شما نتابد. همچنین می توانید از صفحه های فیلتر نیزبر روی صفحه مانیتور استفاده كنید. تابش نور به صفحه مانیتور سبب كاهش كنتراست و خستگی چشم می شود. این مساله بخصوص زمانیكه زمینه صفحه تیره باشد شدیدتر خواهد بود.

4- به چشمان خود استراحت دهید. سعی كنید هر 5 تا 10 دقیقه چشم خود را ازمانیتور برداشته و به مدت 5 تا 10 ثانیه به نقطه ای دور نگاه كنید، این كار سبب استراحت عضلات چشم می شود. همچنین به شما وقت می دهد پلك بزنید و سطح چشم شما مرطوب شود.

5- اگر مجبورید كه متناوباً به یك صفحه نوشته و مانیتور نگاه كنید (خصوصاً در مورد تایپیست ها) ممكن است چشم شما خسته شود زیرا باید تطابق خود را تغییر دهد. برای جلوگیری از این مساله سعی كنید صفحه نوشته شده را در حداقل فاصله و هم سطح با مانیتور قرار دهید. برای اینكار می توانید ازCopyholder استفاده كنید.

6- فاصله مانیتور با چشمان شما باید 50 تا 60 سانتی متر باشد.

7- روشنایی و كنتراست مانیتور خود را تنظیم كنید. میزان روشنایی مانیتور باید با روشنایی اتاق هماهنگی داشته باشد. یك روش برای تنظیم روشنایی مانیتور ایناست كه به یك صفحه وب با زمینه سفید (مثل این صفحه) نگاه كنید. اگر سفیدی صفحه برای شما مثل یك منبع نور است روشنایی مانیتور زیاد است و باید آن را كم كنید. در مقابل، اگر صفحه كمی خاكستری به نظر می رسد روشنایی را زیاد كنید. در مجموع روشنایی باید در حدی باشد كه چشمان شما احساس راحتی كنند. كنتراست مانیتور باید حداكثر باشد تا لبه حروف بیشترین كنتراست را با نوشته خود پیدا كند.

8- مشخصات دیگر مانیتور خود را تنظیم كنید، كیفیت نمایش تصاویر بر روی مانیتور به سه عامل بستگی دارد:Resolution،Refresh Rate وDot Pitch.

Refresh Rate نشاندهنده فركانس تجدید تصویر بر روی مانیتور است. فركانس پایین می تواند برای چشم خسته كننده باشد و فركانس های خیلی پایین سبب پرش تصویر می شوند. بهترین Refresh Rate حدود 70 هرتز یا بیشتر است. Resolution یا وضوح تصویر كه بهRefresh Rate نیز بستگی دارد به تراكم پیكسل های تصویر بر روی مانیتور گفته می شود. هر چه تعداد پیكسل ها بیشتر باشد جزئیات بیشتری از تصویر دیده می شود. بطور كلی هر چه Resolution بیشتر باشد بهتر است ولی باید به Refresh Rate نیز توجه داشت. گاهیResolution بالا Refresh Rate پایین دارند بنابراین باید وضعیتی را انتخاب كرد كه هر دو بیشترین تعداد را داشته باشند.

9 - Dot pitch برsharpness تصویر موثر است و هر چه عدد آن كمتر باشد تصویرSharpتر است. بیشتر مانیتورها Dot pitch بین 25/0 تا 28/0 میلی متر دارند. 28/0 میلی متر یا كمتر عدد مطلوب است.Refresh Rate وResolution را در ویندوز می توانید در Properties Display تنظیم كنید ولیDot pitch قابل تنظیم نیست. eResearch by Navid Ajamin -- spring 2009

10 - اگر علی رغم رعایت توصیه های گفته شده بازهم دچار علائمCVS هستید می توانید از عینك های مخصوص استفاده كنید زیرا گاهی مشكل در دید متوسط است. ما بطور معمول كمتر از دید متوسط استفاده می كنیم زیرا بیشتر اوقات یا اشیاء دور را نگاه می كنیم و یا اشیاء نزدیك. ولی مانیتور كامپیوتر دقیقاً در فاصله ای از چشم قرار می گیرد كه مربوط به دید متوسط است. اگر شما عینكی هستید عینك شما به احتمال زیاد برای كار با كامپیوتر مناسب نیست زیرا دید متوسط را اصلاح نمی كند. برای دریافت عینك مناسب كامپیوتر به چشم پزشك مراجعه كنید.

11- هنگام كار با كامپیوتر سعی كنید گردن خود را راست نگهداشته و شانه را عقب دهید. قوز كردن هنگام كار طولانی با كامپیوتر سبب دردهای گردن و شانه ها می شود. اگر پشتی صندلی شما قابل تنظیم است آن را طوری تنظیم كنید كه كاملاً به پشت شما بچسبد. همچنین ارتفاع صندلی خود را طوری تنظیم كنید كه كف پاها روی زمین قرار داشته و زانوی شما در زاویه 90 درجه قرار داشته باشد.keyboard وMouse باید پایین تر از آرنج و نزدیك دستان شما قرار داشته باشد.

و نهایتاً اینكه: اگر همچنان بر اثر كار با كامپیوتر دچار مشكلات چشمی هستید بهتر است به یك چشم پزشك مراجعه كنید.

See also:

• How Proper Computer Ergonomics Reduces Back Pain
• Treatment for Computer Vision Syndrome - Saint Luke's

Visual Display Unit (VDU)

Short for visual display unit, VDU is an older British term used to describe any device used with computers to display images. For example, a flat panel display and a projector are both examples of VDUs. However, VDU is most commonly used to describe the CRT monitor, a now archaic standard that has been replaced by flat panel displays.

VDU's and Your Eyes. Although there is no reliable evidence to suggest that even long-term intensive use of VDUs is damaging to the eyes, it is true that VDU users tend to complain of eye strain more than non-users.

Symptoms can range from tired eyes to blurred vision. If VDU operators do experience any of the following symptoms they could have computer vision syndrome. If they find it difficult to focus on distant objects after using a computer, have headaches, eyestrain or dry eyes they need to take extra care when using a VDU.

More people are now using computers for work causing a marked increase in the number of people complaining of eye strain. According to the Health and Safety Executive (HSE) extensive research has found no evidence that visual display units (VDU‟s) can cause disease or permanent damage to eyes. However extended or prolonged periods of VDU work can lead to tired eyes and discomfort. As the eyes now perform more demanding tasks, it may make VDU workers more aware of an eyesight problem. It may also make those with pre-existing vision defects more aware of them if these are not corrected. Computer vision syndrome is also a common eye condition amongst VDU users.

With the rising number of people using computers at work and at home there has also been an increase in the number of people complaining of eye strain. Although scientific research has not proved a link between using computers and permanent eye damage using VDUs for a long period of time can cause some minor eye problems.

Computer vision syndrome is a common eye condition amongst VDU users. Symptoms can range from tired eyes to blurred vision. If you do experience any of the following symptoms you could have computer vision syndrome. If you find it difficult to focus on distant objects after using a computer, you have headaches, eyestrain or dry eyes you need to take extra care when using a VDU to avoid getting computer vision syndrome. It is also best to visit your optician for an eye test to rule out anything more serious.

Several symptoms can indicate digital eye strain, including:

• Sore, tired, burning or itching eyes
• Watery or dry eyes
• Blurred or double vision
• Headache
• Sore neck, shoulders or back
• Increased sensitivity to light
• Difficulty concentrating
• Feeling that you cannot keep your eyes open

Common causes of eyestrain include:

• Looking at digital device screens
• Reading without pausing to rest your eyes
• Driving long distances and doing other activities involving extended focus
• Being exposed to bright light or glare
• Straining to see in very dim light
• Having an underlying eye problem, such as dry eyes or uncorrected vision (refractive error)
• Being stressed or fatigued
• Being exposed to dry moving air from a fan, heating or air-conditioning system

There a number of things you can do to look after your eyesight when using VDUs. Follow the following advice to ensure good eye health:

Computer use strains eyes more than reading print material because people tend to:

• Blink less while using computers (blinking is key to moistening the eyes)
• View digital screens at less than ideal distances or angles
• Use devices that have glare or reflection
• Use devices with poor contrast between the text and the background

Some other factors that can make the condition worse include:

• Glare on your screen
• Poor posture
• Setup of your computer workstation
• Circulating air, such as from air conditioning or a nearby fan

Tips for preventing eye strain

• Using eye drops. A person blinks less than usual when using digital screens, and this can dry out the eyes. Drops or artificial tears can be purchased at most pharmacies, as well as online. Specialty eye drops are available for people who wear contact lenses. Preservative-free eye drops are best.
• Change computer settings. Making text twice as large as usual can reduce eye strain. Reading black text against a white background is easiest on the eyes.
• Reduce screen glare. Protective anti-glare screens can be applied to computers and eyeglasses, to prevent eye problems. Also, flat screens tend to have less glare than curved ones.
• Adjust the screen's contrast. Change settings so that the screen is bright enough to read the text without straining. The right contrast may change, depending on the presence of sunlight.
• Get regular eye checkups. Poor eyesight is a major cause of strain. Regularly attending checkups will ensure that a person has an updated prescription when needed.

Visual

A. Adjust screen angle to suit sitting height. Slightly downward viewing angle i.e. 20-40o from horizontal
B. Adjust display height to minimise head/neck movement.
C. Adjust screen to avoid/minimise reflections and glare.
D. Adjust screen brightness and contrast
E. Vary viewing distance over working day.

Additionally:

• Where document holders used, place at same height, plane and viewing distance as screen to minimise head/neck/eye movement.

• Adjust blinds to minimise glare.

Posture eResearch by Navid Ajamin –- Spring 2008

1. Adjust backrest to support lower back
- Do not slouch
- Sit right back in chair to gain proper support
2. Adjust seat height so have room between legs and table.
3. Knees level with hips
4. Elbows close to sides
3. Adjust height so forearms horizontal
4. Wrist slightly flexed
5. Keep a clear area in front of keyboard to rest wrists when not typing consider using a wrist rest
6. Use foot rest, if required
7. Keep mouse and keyboard within easy reach, avoid over stretching to use mouse

Organisational

• Keep area under desk clear. Remove obstacles.

• Move PC tower unit if this is restricting leg movement.

• Keep desk as clear as possible,but …
  … with supplies close at hand.

• Keep space into/out of workstation clear and free of obstructions.

• Take short breaks every now and again.

• Break-up VDU work with non VDU work

• “Stretch your legs”.

• Rest arms and shoulders periodically.

• Avoid high activity wrist movements during work breaks.

Reference:

unison.org.uk eyehelp.co.uk mayoclinic.org medicalnewstoday.com eyecaretrust.org.uk

9 Ways to Reduce the Symptoms of Computer Eyestrain

Eyestrain is the number one complaint in office jobs, but there are many things workers and employers can do to reduce these symptoms. The best solution is number 1 below—see an eye doctor using the PRIO Vision Tester, and get a pair of eyeglasses specifically to wear when you use the computer.

The potential impact of computer use on children’s vision involves the following factors:

• Children often have a limited degree of self-awareness. Many children keep performing an enjoyable task with great concentration until near exhaustion (e.g., playing video games for hours with little, if any, breaks). Prolonged activity without a significant break can cause eye focusing (accommodative) problems and eye irritation.

Accommodative problems may occur as a result of the eyes’ focusing system “locking in” to a particular target and viewing distance. In some cases, this may cause the eyes to be unable to smoothly and easily focus on a particular object, even long after the original work is completed.

Eye irritation may occur because of poor tearflow over the eye due to reduced blinking. Blinking is often inhibited by concentration and staring at a computer or video screen. Compounding this, computers usually are located higher in the field of view than traditional paperwork. This results in the upper eyelids being retracted to a greater extent. Therefore, the eye tends to experience more than the normal amount of tear evaporation resulting in dryness and irritation.

• Children are very adaptable. Although there are many positive aspects to their adaptability, children frequently ignore problems that would be addressed by adults. A child who is viewing a computer screen with a large amount of glare often will not think about changing the computer arrangement or the surroundings to achieve more comfortable viewing. This can result in excessive eye strain. Also, children often accept blurred vision caused by nearsightedness (myopia), farsightedness (hyperopia), or astigmatism because they think everyone sees the way they do. Uncorrected farsightedness can cause eye strain, even when clear vision can be maintained.

• Children are not the same size as adults. Since children are smaller, computers don’t fit them well. Most computer workstations are arranged for adult use. Therefore, a child using a computer on a typical office desk often must look up further than an adult. Since the most efficient viewing angle is slightly downward about 15 degrees, problems using the eyes together can occur. In addition, children may have difficulty reaching the keyboard or placing their feet on the floor, causing arm, neck or back discomfort.

• Children often use computers in a home or classroom with less than optimum lighting. The lighting level for the proper use of a computer is about half as bright as that normally found in a classroom. Increased light levels can contribute to excessive glare and problems associated with adjustments of the eye to different levels of light.

Here are nine additional tips for ways to reduce eyestrain.

1. GET AN EYE EXAM!

This is the most important thing you can do to prevent or treat computer vision problems.

According to the National Institute of Occupational Safety and Health (NIOSH), computer users should have an eye exam before they start working on a computer and once per year thereafter.

2. USE PROPER LIGHTING

In your office you are likely to find several things that can cause eyestrain, including glare on walls and finished surfaces, reflections on the computer screen itself, excessively bright light coming in from outside, and excessively bright light inside

Eliminate exterior light and reflections by closing drapes or blinds.

When using computers, lighting should be about half that used in most offices. Reduce lighting by using fewer light bulbs or florescent tubes, or use lower intensity bulbs and tubes.

3. TAKE FREQUENT BREAKS

Full time computer users should take a 10-minute break every hour to reduce eyestrain problems according to experts. Part-time users should take frequent breaks, after sitting in front of their display for more than a hour.

4. REFOCUS YOUR EYES

Look away from your computer screen every 10-15 minutes and focus for 5-10 seconds on a distant object outside or down the hallway. This prevents the fixed gaze common among computer users. It also lets you blink, which wets your eyes.

5. BLINK MORE OFTEN

When staring at a computer, people blink less frequently—about 5 times less than normal, according to studies. Tears coating the eye evaporate more rapidly during long non-blinking phases and cause dry eyes. Office buildings may have excessively dry environments that also reduce tearing. For significant problems, ask your eye doctor about artificial tears or eye drops that you can use during the day.

6. MODIFY YOUR WORKSTATION

If you need to look back and forth between the printed or written page and the computer, this can cause eyestrain. Place written pages on a copy stand adjacent to the monitor. Properly light the copy stand. Adjust your workstation and chair to the correct height. Purchase ergonomic furniture to assure proper screen locations and posture.

7. MATCH THE COMPUTER SCREEN TO THE BRIGHTNESS OF THE ENVIRONMENT

Closely match the brightness of the environment with that of the computer screen. The contrast between the background and on-screen characters should be high.

8. MINIMIZE GLARE

Use window shades, blinds or drapes to block out excessive sunlight, or install an anti-glare screen, to minimize reflections on the screen itself. Reduce the internal ambient light if necessary. For conditions where outside light cannot be reduced, use a computer hood to cut glare and reflection. Have an Anti-Reflective coating applied to your glasses. This will prevent glare and reflections on the back side of your lenses form reaching your eyes.

9. EXERCISE EVEN WHEN SITTING

Anyone in a sedentary job, especially those using computers, should also stand up, move about, or exercise frequently. NIOSH recommends several sitting, stretching, and joint rotating exercises for computer users.

As parents or carers, it is essential to recognise the signs of Digital Eye Strain in children.

Some common symptoms include:

• Eye discomfort: Complaints of tired, itchy, or burning eyes.
• Squinting or blinking: Frequent squinting or blinking to refocus their vision.
• Headaches: Recurring headaches, especially after screen time.
• Dry eyes: Experiencing dryness or grittiness in the eyes.
• Double vision: Temporary vision issues like double vision or blurred vision.

Reference:

• yesite.co.za/2004/04/15/impact-of-computer-use-on-childrens-vision
• visiondirect.com.au/optical-centre/eye-care/digital-eye-strain
• gormleyopticians.com/protecting-childrens-eyes-digital-strain
• prio.com/consumers/9ways.cfm

Can computer screens cause blurry vision?

Upwards of 90% of screen users experience eye strain known as computer vision syndrome, or CVS. It's a reality for many in today's technology-driven world, and can lead to symptoms such as: Decreased or blurred vision. Burning or stinging eyes.

Can eye strain cause double vision?

Eyestrain symptoms include: Sore, tired, burning or itching eyes. Watery or dry eyes. Blurred or double vision.

Can too much screen time cause diplopia?

Double vision, or diplopia, is the perception of two images from a single object. And staring at a computer screen for too long may cause this. But if double vision persists, it can indicate a severe neurological problem for which you should immediately see your eye doctor.

Can prolonged screen time cause double vision?

Yes. Digital eye strain can cause many symptoms, including: Blurred vision. Double vision. Dry eye.

Can you cure computer vision syndrome?

Does computer vision syndrome go away? Often, reducing your amount of screen time can help symptoms go away. But if you need to keep using digital devices every day, symptoms may keep returning. Or they may get worse.

Recent studies indicate that computer vision syndrome (CVS) affects as many as 75% of computer users. CVS presents when a person spends a good deal of time working or in front of a computer. This vision condition is not extremely dangerous, and there is no reason to panic if you experience some of the symptoms described, but know that you can reduce these symptoms with CVS by just changing the way you work at your computer.

Computer vision syndrome is a new problem that has emerged in this century following increase usage of computer both at home and at work. There is a correlation between ocular symptoms such as pain, redness, dryness, blurring of vision, double vision and other head and neck sprains and computer usage. eResearch by Navid Ajamin -- spring 2008

With glasses for the computer, you will sharpen visual focus and you will see with more clarity. Clarity with reduced glare helps your eyes feel better at work. Long hours in front of a computer screen and harsh fluorescent lighting can produce CVS and dry eyes.
Dry eye syndrome can also start with the patient who suffers from CVS. Computer users don’t blink enough to keep their eyes moist.

They compensate to see the screen by bending their heads down to look over their glasses or holding their chin up to see through the lower part of their lenses, causing aches. To that fact, you will find that most patients with CVS also have tired and sore back and neck pain at work.

Without proper glasses and Rx for computer distance, the patients with CVS will also experience headaches, blurred vision and general fatigue.

Anyone who spends several hours in front of a computer screen is at risk for CVS.

The US Occupational Safety and Health Administration estimates that more than 90% of all computer workers suffer from CVS when spending time in front of their computers for more than three hours a day.[1]

Asthenopic (eye strain) symptoms in the eye are responsible for much of the severity in CVS. Proper rest to the eye and its muscles is recommended to relieve the associated eye strain. Observations from persons experiencing chronic eye strain have shown that most people who claim to be getting enough sleep are actually not. This, unaware to them, causes the eye strain to build up over a period of time, when if they had obtained seven to eight hours of uninterrupted sleep, their eye muscles would have recovered during the sleep and the strain would not have built up.

Computer workers are often advised to take breaks and look at distant objects. A routinely recommended approach is to consciously blink the eyes every now and then (this helps replenish the tear film) and to look out the window to a distant object or to the sky—doing so provides rest to the ciliary muscles.

One of the catch phrases is the "20–20–20 rule":every 20 minutes, focus the eyes on an object 20 feet (6 meters) away for 20 seconds. This basically gives a convenient distance and timeframe for a person to follow the advice from the optometrist and ophthalmologist. Otherwise, the patient is advised to close their eyes (which has a similar effect) and relax the face and neck muscles for two minutes, at least every half-hour.

A number of computer and smartphone applications, such as f.lux, redshift and Night Shift adjust the computer video color temperature, reducing the amount of blue light emitted by the screen, particularly at night.

Blue-light blocking glasses have filters in their lenses that block or absorb blue light, and in some cases UV light, from getting through. That means if you use these glasses when looking at a screen, especially after dark, they can help reduce exposure to blue light waves that can keep you awake.

Dry eye is a symptom that is targeted in the therapy of CVS. The use of over-the-counter artificial-tear solutions can reduce the effects of dry eye in CVS. Prior to using artificial tear solutions, it is necessary to check if dry eye is the actual cause of the problem (measured by a tear meniscus test) or whether there are no actual symptoms of dry eye at all. Dry eyes because of CVS can also be treated using moisture chamber glasses or humidifier machines. Office spaces with artificially dry air can worsen CVS syndromes, in which case, a desktop or a room humidifier can help the eyes keep a healthy moisture level.

Is Dark mode better for eyes?

Dark mode doesn't directly reduce eye strain, but it can offer some relief. For example, in a dim setting, a bright screen has your eyes working harder. On the contrary, a dark screen in a brightly lit room will have the same effect.

At night, CVS can become worse. It is recommended to use a dark user interface while working at night on the computer. Several browser and OS add-ons exist to darken the user interface.

When working on computer screens people tend to blink less which leads to the eyes drying out faster. Reminding people to blink or do blinking exercises is achieved via static reminders.

A 2017 randomized controlled trial evaluated macular carotenoid supplements (lutein, zeaxanthin, and mesozeaxanthin) in people with high screen time usage. The supplement group had statistically significant reduction in self-reported headache, eye strain, eye fatigue and sleep complaints, but no reduction in neck strain or blurry vision.[2]
If you think you might be experiencing some of these symptoms, we recommend you have an eye exam to test for CVS symptoms.

We also recommend that you modify your work station at your computer and make sure you have proper lighting and chair positioning to reduce your fatigue and neck strain associated with working on your desk and computer terminal.

Reference:

1. siouxfallsfamilyvision.com
2. en.wikipedia.org/wiki/Computer_vision_syndrome
3. ncbi.nlm.nih.gov/pmc/articles/PMC4170366/...
4. pubmed.ncbi.nlm.nih.gov/34160157
5. cedars-sinai.org/health-library/diseases-and-conditions/c/computer-vision-syndrome.html

See also:

• Easy Solutions for Screen-Related Eye Issues
• How do you relax your eyes after long screen time?

Computer vision syndrome (CVS) is a condition resulting from focusing the eyes on a computer or other display device for protracted, uninterrupted periods of time and the eye muscles being unable to recover from the strain due to a lack of adequate sleep.

Computer Vision Syndrome, also referred to as Digital Eye Strain, describes a group of eye and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use. Many individuals experience eye discomfort and vision problems when viewing digital screens for extended periods.

Many of the symptoms of CVS can be broadly classified as "asthenopia". Most of these symptoms are also associated with other forms of near work. Neck and/or backaches are listed as a symptom of CVS since the eyes lead the body. Computer workers will often assume awkward postures in order to position their eyes so that they can perform their work - resulting in these musculoskeletal symptoms.

This can be the result of a poorly designed work station, assuming awkward postures due to using spectacles which are improperly designed for the task or due to making accommodations for a particular eye/vision disorder.

Asthenopia is more commonly known as eyestrain or ocular fatigue. It’s a common condition that occurs when your eyes become tired from intense use.

Staring at a computer screen for long periods or straining to see in dim light are common causes.Most of the time, asthenopia isn’t serious and goes away once you rest your eyes. Sometimes, asthenopia is related to an underlying vision problem, such as astigmatism or farsightedness (hyperopia).

Causes of asthenopia

Prolonged use of computers and digital devices has become such a common cause of asthenopia that it has been dubbed “computer vision syndrome” or “digital eyestrain.”

Along with staring at screens for extended periods, other causes of asthenopia include:

• reading for long periods
• staring to see in dim or dark surroundings
• driving long distances
• exposure to bright light or glare
• activities involving intense focus
• being stressed or fatigued
• exposure to dry moving air, such as a fan, air conditioning, or heater
• underlying eye conditions, such as dry eye or uncorrected vision

Computer Vision Syndrome (CVS) Symptoms

In most cases of CVS, the clinician is able to establish a visual diagnosis for the symptoms being experienced.

There are numerous accommodative disorders (e.g., decreased amplitude or infacility of accommodation) and binocular vision dysfunctions (e.g., phoria, strabismus) that can clearly cause the symptoms.

Uncorrected or improperly corrected presbyopia (improper add/or spectacle design) can also result in symptoms. Hyperopia can result in visual symptoms - especially in near workers. Uncorrected astigmatism can also cause symptoms because of the acuity demands of the task.

In some cases myopia can cause a blurred view of the computer screen and/or awkward posture. There is also some evidence to indicate that near work causes the development of myopia in some individuals. A dry eye condition is one which can be exacerbated by computer work due to staring, elevated gaze angle, decreased blinking, and a low humidity environment.

The symptoms of CVS can vary from person to person but commonly include:

1. Eye Strain: (Non-Specific Ocular Discomfort) Aching, burning, or heavy feeling in the eyes.
2. Headaches: Frequent headaches, often starting at the forehead and temples.
3. Blurred Vision: Difficulty focusing on the screen or other objects, both near and far.
4. Dry Eyes: Reduced blinking while using screens can lead to dry, irritated eyes.
5. Irritated Eyes
6. Double Vision: (Diplopia) Seeing two images of the same object on the screen.
7. Neck and Shoulder Pain: Poor posture while using digital devices can cause neck and shoulder discomfort.
8. Difficulty Concentrating: Reduced concentration and increased irritability.
9. Fatigues

Each of the CVS diagnoses presented can be treated - usually with a good prognosis for eliminating or reducing the presenting symptoms.

Computer Vision Syndrome (CVS) Visual Diagnoses

• Binocular Vision Dysfunctions
• Accommodative Disorders
• Refractive Errors
• Astigmatism
• Presbyopia
• Hyperopia
• Dry Eyes
• Myopia

CVS symptoms occur as a result of visual interaction with a task (the computer display) which stresses the visual system. The occurrence of symptoms depends upon the magnitude of any existing visual disorder as well as the demand level of the task. The task demand level can be dependent upon many variables. There are particular environmental factors associated with work at a computer which make it more visually demanding than other near point tasks.

Environmental Factors of Computer Workstations

• Contrast and resolution of the display
• Room lighting
• Viewing distances and angles
• Sustained viewing
• Adjustability of workstation

Appropriate diagnosis and treatment of existing vision problems and control or elimination of environmental factors can effectively reduce the symptoms associated with computer vision syndrome. eResearch by Navid Ajamin -- Spring 2008

What Else Contributes to Computer Vision Syndrome & Digital Eye Strain?

Not surprisingly, the biggest contributing factor to CVS is how much time one spends viewing screen-based devices (including your phone, tablet, e-readers, and other electronic devices). In our constantly connected, hyper-digital society, it is likely that many of us are accumulating at least seven hours of screen time per day. For someone with a computer-based job, that number is likely even higher.

In addition to screen use, other factors such as allergies, preexisting eye or vision problems, and a poor work environment can also lead to the development of CVS. Components of a poor work environment may include:

• Room lighting that is too strong or too dim
• Device screen that is too bright or too dim
• Glare on the device screen
• On-screen text that is too small
• Poor screen placement (too far, close, low, or high)
• Lack of ergonomic desk, seating, keyboard, or mouse
• Poor posture while using any screen (not just a computer screen)

Steps You Can Take to Protect Your Children from CVS

There are many things you can do to reduce your child’s risk of developing CVS. These include:

• Teaching your child about the risks of spending too much time staring at a screen.
• Limiting screen time to one or two hours a day.
• Making your child’s work station more ergonomic — make sure the lighting is adequate (too much light can create glare); chairs should be positioned at a comfortable distance; and the screen should be in the correct position as well — slightly below your child’s eye line and about 18 to 28 inches away.
• Scheduling regular eye exams for your child.
• Getting your kids in the habit of following the 20-20-20 rule: Take 20 seconds to look at something 20 feet away every 20 minutes.
• Wearing computer glasses to help your child’s eyes more easily focus on the computer screen.
• Anti-glare screens or anti-glare coatings on eyeglasses can help reduce glare and eye strain.
• Watching your children for signs of CVS — red eyes, blurred vision, eye rubbing, or stiff neck.

If these symptoms persist, take your child in for an eye exam.

Reference:

• continentalhospitals.com/blog/tips-for-preventing-computer-vision-syndrome-in-children-and-adults
• rochesteroptical.com/optometrist-rochester/what-is-computer-vision-syndrome
• berkeleyeye.com/blog/children-and-computer-vision-syndrome
• healthline.com/health/asthenopia#causes
• eyestraingone.com
• insightseyecare.net
• en.wikipedia.org
• aoa.org

See also: 6 Ways to Effectively Manage Computer Vision Syndrome

Using a Computer

    Spending a lot of time at your computer may cause eye strain and dry eye, although it won't damage your eyes. Many of the same steps used to minimize eyestrain from watching TV will also help protect your eyes when you're using a computer. You may need to get proper eyeglasses to make sure you can read the screen easily without being too close or too far away. If your eyes bother you when you are working at a computer, consult your eye care professional to find out whether you have the right prescription for your glasses. You will also help easy eyestrain by taking regular rest breaks. Try to blink often to keep your eyes from drying out.
In addition, you can adjust your workstation, as follows:

Sit about 20 inches from the computer monitor, with the top of the screen at or below eye level.
Use a monitor that tilts or swivels and has controls for contrast and brightness.
Use an adjustable chair.
Place working documents on a document holder so you don't have to keep looking back and forth.
To eliminate reflections or glare, adjust your office lighting or use a hood or micromesh filter for the computer screen. 

Reference: www.novartisophthalmics.com

14 Tips for Healthy Computing:

1. Make your workstation fit you. Since we all come in different shapes and sizes, you need to know what is the optimal ergonomic setup for your body.
2. If you use a laptop for longer than two hours without proper ergonomics it can wreak havoc on your body. You can minimize these problems by using a laptop mount or lift arm.
3. Position the monitor no closer than 20 inches (508 mm) from your eyes. A good rule of thumb is an arm’s length distance.
4. Adjust your monitor height so that the top of your screen is at or slightly below eye level. Your eyes should look slightly downward when viewing the middle of the screen.
5. Adjust your screen position to eliminate glare from windows and ceiling lights.
6. If lighting conditions permit, tilt your monitor back 10° to 20°: this maintains the same distance between your eyes and the screen as you scan it from top to bottom. Exception: If using bifocals, lower the monitor below eye level and turn screen upward,tilting it back 30° to 45°.
7. The center-line of the keyboard should be level with the height of your elbow.
8. Tilt the keyboard back 10° so that your wrists remain flat.
9. Use an adjustable chair. Get comfortable with its features and make adjustments regularly.
10. Rest your eyes periodically by focusing on an object 20+ feet away.
11. Stand and stretch your back and arms from time to time.
12. Position whatever you are looking at most of the time (the screen or reference material) directly in front of you to minimize turning your head.
13. Remember that even if your workstation is set up properly, you can still get muscle fatigue from being in the same position for too long. Be sure to periodically adjust your monitor, keyboard or chair to stay flexible.
14. Minimize the amount of time you spend using a laptop without proper ergonomic height adjustment. I know you own a laptop because it allows you to work in the coffee shop, on a park bench, at the swimming pool or from any room in your home and it’s okay in moderation, but prolonged use of a laptop in a non-ergonomic environment can have long term consequences.

Reference:

• steve-olson.com/14-tips-for-healthy-computing
• yourdictionary.com/articles/computer-terms-kids
• xda-developers.com/tips-set-safe-parental-controls-windows-child-safety

به نام خالق زیبایی ها

• نسخه های پزشکی دیگران را کپی نکنید. Translation: Navid Ajamin -- winter 2004
• در حد امکان روزانه از سبزیجات تازه٬ گوجه فرنگی٬ هویج و یک لیوان شیر استفاده کنید.
• چشمان خود را در برابر تشعشعات ماورای بنفش٬ گرد و غبار٬ باد و نور زیاد حفظ کنید.
• چشمان خود را در ساعتهای کاری زیاد استراحت بدهید.
• چشمان خود را با ملایمت و مقدار کافی آب روزانه بشوئید.
• همیشه در محیط نوری مناسب و با قرار گرفتن صحیح بدنتان مطالعه کنید.
• بدنتان را در موقعیتی صحیح و با استراحت در فاصله های کاری حفظ کنید.
• درهنگام مطالعه اگر مشکلی دارید و یا عیوب انکساری دارید از عینک استفاده کنید.
• از قطره های چشمی تنها از آنچه برایتان تجویز شده استفاده کنید.
• هنگام کار با کامپیوتر فاصله ایی صحیح از کامپیوتر و لوازمات کامپیوتری داشته باشید.

Healthy vision starts with you! Use these 10 tips to take care of your eyes.

1.Eat right to protect your sight.

Keep your eyes healthy by eating a well-balanced diet. Load up on different types of fruits and veggies, especially leafy greens like spinach, kale, and collard greens. Fish like salmon, tuna, and halibut have been shown to help your eyes, too.

2.Get moving.

Did you know that kids who exercise often have a healthier body weight than kids who don’t? Being overweight or obese can put you at higher risk for diabetes and other conditions that can lead to vision problems.

3.Speak up if your vision changes.

Is your vision blurry? Do you squint a lot? Ever have trouble seeing things at school? Tell a parent or teacher if your eyes are bothering you or if you notice any changes in your vision.

4.Wear your glasses.

Your glasses help you see better, especially when they’re clean and free of smudges. Talk to an adult about how to clean your glasses and how to store them when you’re not wearing them.

5.Keep the germs away.

Always wash your hands before putting them close to your eyes, especially if you’re putting in or taking out contact lenses.

6.Gear up.

Playing your favorite sport? Using chemicals during science class? Mowing the lawn? Wear the right protection to keep your eyes safe. Many eye injuries can be prevented with better safety habits, such as using protective eyewear.

7.Wear your shades.

The sun’s rays can hurt your eyes. Choose sunglasses that block 99% or 100% of both UVA and UVB radiation from the sun. And remember, you should never look directly at the sun.

8.Give your eyes a break.

Do you spend a lot of time looking at a computer, phone, or TV screen? Staring at any one thing for too long can tire your eyes. Give your eyes a rest with the 20-20-20 rule: Every 20 minutes, look about 20 feet away for 20 seconds.

9.Say no to smoking.

Did you know that smoking is as bad for your eyes as it is the rest of your body? Smoking can put you at risk for some pretty serious eye issues, which can lead to blindness.

10.Talk about it.

Does anyone in your family have issues with their eyes? Not sure? Ask! Talking about eye health with your family can help all of you stay healthy.

Reference: https://www.nei.nih.gov/learn-about-eye-health/nei-for-kids/healthy-vision-tips

Video: eyecare tips See also: Simple Tips for Healthy Eyes