عینک eyewear

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.

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?

Scratch-resistant means a surface or material that is resistant to scratches than an unprotected surface, but can still be scratched.

Scratch-proof is a quality of a product that implies the toughness of that particular product. This means no amount of external pressure can break the product.

[4] Prescription eye-ware and Sunglasses

To make surfaces of eye ware scratch resistant, an external coating is generally applied on it that prevents minor damage. This is a very thin coating is made from diamond like carbon and polycrystalline material which does not hamper the vision of the person wearing it. This coating only prevents minor damage and does not offer a long term protection. Other products that come with this protection include camera lenses, iPods and MP3 players, computer screens, DVDs and CDs, cars, and so on.

Thus, the difference between scratch proof and scratch resistant is more a matter of semantics than anything else. It is best to take proper care these items, and store these products in a safe place to avoid scratches. Once damaged, it is not possible to repair these scratches and most likely the item will need to be replaced.

what to expect from your new glasses
If you are getting eyeglasses for the first time, or getting a new prescription, please allow 1-2 weeks for your eyes to adjust to the new lenses. In the beginning, you could experience mild dizziness, headaches or even slight nausea. These symptoms are normal; however, if they persist, call your optician office.

If you experience any problems with your new frames, including discomfort on the nose or ears, return to your optician office for an adjustment. Also, your glasses should remain stationary on your face when you nod or turn your head. If your glasses slide down your nose or tilt to one side, they will be happy to adjust them for you. Please do not try to adjust them yourself.

caring for your new glasses
Always keep your glasses in a case when not in use. This will protect your lenses from scratched and will also help to extend the life of your frame.
To avoid scratching, never lay your lenses directly on any type of hard or abrasive surface.

Be sure to use two hands when putting on or removing your glasses. One-handed techniques are one of the most common cause of glasses coming out of alignment.

Never wear your glasses on the top of your head. This can cause your glasses to lose their shape.
Your glasses will last longer if you have them adjusted periodically. This allows us to check for loose screws or other possible problems. If your frame breaks, do not attempt to repair it with tape or glue. Bring it to us, and we will repair it properly.

cleaning your new glasses
Clean your frames and lenses on a regular basis.
Use a mixture of 50:50 rubbing alcohol and water in a squirt bottle. This is the best solution to remove any smudges or oils on the lenses. Then use a 100% cotton cloth or the provided microfiber cloth to dry them.
To avoid scratching, never wipe your lenses when they are completely dry. Never use any paper
products, i.e., paper towels or tissues.[1] eResearch by Navid Ajamin -- summer 2012

How To Prevent Scratching Your New Glasses

There is nothing worse than spending $500 on a beautiful pair of glasses with high quality lenses and scratching them shortly after your purchase. Scratching your lenses is usually never covered under your warranty. That is because it is 100% preventable. So you may ask, what can I do to prevent scratching my glasses? Here are some steps to help keep your glasses looking new.

1. Keep your glasses on your face and when they are not on your face put them into a glasses case.
2. Do not drop your glasses. Large scratches are usually caused by dropping your glasses on a hard surface.
3. Never store your glasses in your pockets or purse without them being in a glasses case. This includes your shirt pockets, jean pockets, or coat pockets.
4. Clean your glasses regularly.
5. Purchase and anti-scratch coating to help minimize scratches.
6. Anti-reflective coatings can be scratch very easily. It is important to take extra good care of your glasses if you purchase an anti-reflective coating.
7. Never use your shirt or any abrasive material or abrasive soap to clean your glasses.
8. Never set your glasses down on an end table or nightstand without being in a case.
9. Accidents happen and your glasses can easily be knock off a table and scratched or stepped on.
10. For some reason children and dogs like to play with glasses…..to not let them!
11. ALWAYS PUT YOUR GLASSES IN A GLASSES CASE WHEN THEY ARE NOT BEING USED. If your glasses are on your face or in a case you will rarely scratch them.[2]

An anti-scratch or scratch-resistant coating is a film or coating that can be applied to optical surfaces, such as the faces of a lens or photographic film. The coating does not interfere with how the lenses function and does not affect vision, but creates a permanent bond with the lens that reduces the appearance of hairline scratches which is common to eyeglass lenses.

Though an anti-scratch coating is not 100% scratch-proof, it helps to prevent minor scratches that can easily happen to a regular lens. These minor scratches can damage the surface of the lens and impair vision. An anti-scratch coating acts as a protective layer thus making the lenses more durable.[3]

It's best to only use mild washing-up liquid to clean sunglasses. Using materials other than microfibre fabrics, including paper products like paper towels and tissues, can scratch the lenses of your sunglasses. To ensure you don't damage your lenses, it's best to always use a microfibre cloth for cleaning.

Reference:

1. drdodgeod.com
2. visiononesource.com
3. en.wikipedia.org/wiki/Anti-scratch_coating
4. diffen.com/difference/Scratch_Proof_vs_Scratch_Resistant

See Also:

• How to Prevent Scratching Your Glasses
• How to Clean Sunglasses without Scratching the Lenses

In chemistry, hydrophobicity (from the Attic Greek hydro, meaning water, and phobos, meaning fear) is the physical property of a molecule (known as a hydrophobe) that is repelled from a mass of water.

hydrophobicity: noun; the property of being water-repellent; tending to repel and not absorb water / Synonyms for hydrophobic: aquaphobic, water repellent

Do scientists think water is wet? [8]

Water is not wet because wetness arises from the interaction between a liquid and a solid surface. In other words, wetness is a property that occurs when water or another liquid comes into contact with a solid object.

Hydrophobic molecules tend to be non-polar and, thus, prefer other neutral molecules and non-polar solvents. Hydrophobic molecules in water often cluster together, forming micelles. Water on hydrophobic surfaces will exhibit a high contact angle.

Examples of hydrophobic molecules include the alkanes, oils, fats, and greasy substances in general. Hydrophobic materials are used for oil removal from water, the management of oil spills, and chemical separation processes to remove non-polar from polar compounds.

Hydrophobic is often used interchangeably with lipophilic, "fat-loving." However, the two terms are not synonymous. While hydrophobic substances are usually lipophilic, there are exceptions—such as the silicones and fluorocarbons.[1]

A superhydrophobic coating is a thin surface layer that repels water.

It is made from superhydrophobic (ultrahydrophobicity) materials. Droplets hitting this kind of coating can fully rebound.

Superhydrophobic surfaces, possessing a high water contact angle (> 150°) and low sliding angle (< 10°), have attracted considerable attention because of their high water repellency and attractive self-cleaning, anti-corrosion, anti-icing, and anti-fouling properties.[4]

Thin layers of a waterproof substance on the surface of hydrophilic materials. Hydrophobic coatings are often called water-repellent, which is incorrect, since the water molecules are attracted to the coatings, although extremely weakly, rather than repelled by them.

Hydrophobic coatings are produced in the form of monomolecular layers (adsorbed orientated layers one molecule thick) or lacquer films by treating a material with solutions, emulsions, or less frequently, vapors of hydrophobic agents, which are substances that interact weakly with water but attach themselves firmly to a surface. Substances used as hydrophobic agents include salts of fatty acids and such metals as copper, aluminum, and zirconium; cation-active surface-active agents; and low-and high-molecular-weight organosilicon and organic fluorine compounds.

Hydrophobic coatings protect various materials (metal, wood, plastics, leather, and fabric and nonfabric fibrous ma-terials) from the destructive action of water or wetting. They are used particularly extensively in machine building,construction, and textile production.[2]

If you live in a cold climate, nothing is more frustrating than having your eyeglasses fog up when you come in from the cold. This also can be a safety issue, since it limits your ability to see until the fog clears. Lens fogging can be especially dangerous for police officers and other first responders to emergency situations. eResearch by Navid Ajamin -- spring 2012

At least one eyeglass lens coating company (Opticote) has created a permanent coating designed to eliminate this problem. The factory-applied coating — called Fog Free — eliminates the condensation of moisture on lenses that causes fogging.

So your lenses and vision stay clear when you make the transition from a cold environment to a warm one. It may also keep your lenses from fogging up during sports and other times you are hot and perspiring.

Fog Free can be applied to plastic, polycarbonate and other eyeglass lenses, including high-index lenses and Transitions photochromic lenses. The anti-fog coating is applied to the lenses before they are cut to fit into your frame at the optical lab. Ask your optical retailer about pricing and availability.

Fire ants can cluster together to increase their buoyancy – a property that scientists hope to copy to clean up oil spills -- superomniphobic surfaces

In October 2011, Essilor introduced a line of eyeglass lenses called Optifog, which the company describes as "a breakthrough lens with an exclusive anti-fog property."

The anti-fogging property of Optifog lenses is activated by applying a drop of Optifog Activator to each side of the lens, then wiping the lens with a microfiber cloth to thoroughly spread the liquid across the entire lens surface. This treatment keeps the lenses fog-free for up to one week, according to Essilor.

Lens fogging is caused by tiny water droplets that form by condensation on the surface of eyeglass lenses when the lenses are significantly cooler than the surrounding air temperature. Optifog works by uniformly spreading these water droplets across the lens surface so they become invisible, Essilor says.

What is hydrophobic cloth? [6]

Hydrophobic nonwovens are used for products that are intended to provide a dry barrier, while withstanding moisture. Some fibers, such as polyester, naturally have hydrophobic characteristics. In other cases, coatings and treatments can be used to make hydrophobic material from naturally absorbent fiber like cotton.

What is an example of a hydrophobic material? [7]

Hydrophobic molecules are molecules that do not have a charge, meaning they're nonpolar. Hydrophobic materials often do not dissolve in water or in any solution that contains a largely aqueous (watery) environment.

Oil, waxes, and steroids are all examples of hydrophobic materials and molecules.

Optifog lenses are available in plastic, polycarbonate and high-index plastic lens materials, with or without Essilor's proprietary Crizal anti-reflective coating.[3]

Reference:

1. en.wikipedia.org/wiki/Hydrophobe
2. encyclopedia2.thefreedictionary.com/Hydrophobic+Coatings
3. allaboutvision.com/lenses/coatings.htm
4. sciencedirect.com/science/article/abs/pii/S0927775721018422
5. chemistryworld.com/features/superhydrophobic-materials-from-nature/3010321.article
6. wptnonwovens.com/blog/hydrophobic-material-vs-hydrophilic
7. study.com/learn/lesson/hydrophobic-effect-molecules-examples.html
8. clearlyfiltered.com/articles/is-water-wet

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

There are over 143 million adults in America who wear glasses. Many of these adults opt to have an anti-reflective coating applied to their lenses for a variety reasons. Anti-reflective coating not only improves the appearance of the glasses but also the vision seen through the lenses. Additional benefits of anti-reflective lenses include durability, heat resistance, aid in night driving, easy cleaning, and resistance to scratches.

The highest quality anti-reflective coating has a hydrophobic, or water-resistant, layer that is made to prevent water spots from developing on the lens and also makes them much easier to clean. Some anti-reflective coatings also have an oleophobic, or oil-resistant, layer that resists oil from the skin and once again makes it easier to clean smudges off of the lenses.

Today, anti-reflective coatings have even become very popular with sunglasses. When applied to the backside of the sunglass lenses, anti-reflective coating reduces the reflections of the sunlight into the eyes when the sun is coming in from behind.

There are many reasons why an anti-reflective coating is added to the lenses of a pair of glasses or sunglasses. This coating is often chosen for appearance, as it improves transparency and reduces the reflections in the glasses. The anti-reflective coating on lenses makes it easier for a glasses wearer to have direct eye contact with someone else without all of the distractions of reflections.

The anti-reflective coating helps improve driving safety, especially at night, by eliminating distracting headlights and streetlights. This allows drivers to focus more on the road.

Also, while working, the unnatural and artificial lights found in many offices can quickly cause eye fatigue.

Using a computer likewise puts great strain on the eyes. Having an anti-reflective coating applied to lenses will help to protect the eyes while working.

Last but not least, an anti-reflective coating on a lens enhances the quality of a lens and also lengthens its lifetime by providing durability and resistance to water, dirt, and scratches.

The problems glare can cause

So, why do we care about glare? Well, it can present numerous problems for wearers, especially when driving, playing sports and working with computers and other tech with direct light sources. The result is inhibiting vision and attributing to health issues, including eye strain, blurred vision or ‘halos’ around bright lights such as street lamps, headaches, migraines and a significant decrease in concentration and focus when squinting to avoid glare. On the odd occasion, it may not seem like a priority to have anti-glare, but once these health issues become chronic, you can have very real, very uncomfortable health issues to deal with.

Do I need anti-glare lenses?

Anti-glare lenses are suitable for everyone, especially in our predominantly digital workspaces, working from home, TV streaming and internet heavy lives we lead. And while some people suffer from the effects of glare more than others, the exposure to digital screens and then natural light to take a break from them will only ever increase. Computer screens, driving at night, and sun exposure are all very different scenarios that can be marred by the effects of glare. And while AR coating does not guarantee reflection elimination, wearing anti-glare lenses will reduce fatigue in your eyes and headaches as a result by lessening the amount of reflection and light coming through your lenses.

Anti-glare coating is layered on both the front and back end of a lens, designed to manipulate incoming light. It allows your eyeglasses to provide you with optimal vision. An anti-glare coating is incredibly effective when applied, blocking up to 99.5% of incoming light. This makes reflections practically invisible. eResearch by Navid Ajamin -- winter 2011

Glare in your eyes can be hazardous to you and everyone around you. It can obstruct your driving at nighttime and during the day. UV light can be damaging to your eyes as well—too much exposure can lead to diminishing eyesight, dryness, and loss of elasticity.

Reference:

• justeyewear.com
• lensology.co.uk/what-are-anti-glare-glasses
• eyeeffects.ca/what-do-anti-glare-glasses-do

Eyeglasses in various types have different benefits. Prescription eyeglasses are mainly for vision correction and sunglasses are particularly designed to offer protection from UV light. Some people simply wear eyeglasses for a stylish look. Currently eyeglasses are available in a variety of lens materials and frame materials. There are also some lens coatings such as anti-reflective(AR) coating and scratch-resistant coating and so on.

One of the common concerns from eyeglass wearers is that whether anti reflective coating is necessary. In general, the answer is yes. This coating applied on lenses can prevent excessive light from entering the eye. Without proper control of the intense light, the pupil will experience unnecessary strain. eResearch by Navid Ajamin -- spring 2010

Having AR coating on your lenses does not only enhance your look, but they are also beneficial for:

• Reducing glare and reflections.
• Reducing glare at night when driving.
• AR coating helps prevent “digital eye strain” for individuals who work in front of computers all day.
• Enhancing the appearance of your glasses.
• Making the lens appear invisible.

Another advantage of anti-reflective coating is that it can address the problem of halo effect around the headlights of the opposite vehicles during night driving. This effect is quite dangerous because the vision can be distracted. Anti-reflective coating on a lens can effectively deal with this problem.

Computer users can also greatly benefit from lenses with anti-reflective coating. Regular computer users have probably experienced the bothersome glare from special parts of the PC monitor. They are forced to strain the eyes in order to get clear vision, which may lead to irritation or dry eyes. Anti-reflective coating performs well in eliminating glare. Anti-reflective coating is also believed to reduce eye pressure in dim light conditions.

In addition, eyeglasses with anti-reflective coating are particularly favored by individuals who like taking photographs. A disappointing defect of ordinary eyeglasses is that the outside images will hide the eyes while taking a photo. Anti-reflective coating can effectively block out the reflected images. This feature is very exciting and handy for photographers.

On the other hand, glasses with anti-reflective coating also need special care. While offering those benefits described above, anti-reflective lenses are easy to scratch, pick out fingerprints and become dirty. Wearers should use special cleaning tools, rather than ordinary cloth that may cause scratches.

Benefits of Anti-reflective Coating

Many people who wear anti-reflective coating glasses find them to be helpful in the following ways:

1) You see less glare on your vision, making it easier to see in environments where light is present.

2) Helps reduce eye strain by blocking treats conditions such as nearsightedness.

3) Anti-reflective coating glasses will provide better protection from the sun's rays and harmful UV light than regular eyewear.

4) Some people wear anti-reflective coating glasses and prescription lens to reduce the glare of computer screens or for reading in bright environments.

5) Prevents eye fatigue by blocking high-energy visible light, which causes it.

6) Helps protect your eyes from UV rays, glare, and other issues related to the sun.

7) The glare is eliminated, making it more comfortable to work on screens for long periods of time.

8) The lenses on the glasses can be easily removed for cleaning, which keeps them from getting dirty and makes your vision clearer.

9) Anti-reflective coating reduces any level of reflecting that might happen when you're looking at a light source like a computer screen or television.

10) It helps to reduce the amount of glare that you see when looking at a window or other reflective surface.

11) Anti-reflective coating lenses are much cheaper to replace than prescription glasses, making them more accessible for those who might not otherwise be able to afford them.

12) They can help you focus on details better than ordinary eyeglasses would be able to do. This makes them great for use in low light conditions or when doing detailed work such as working with small objects like jewelry or electronics.

13) They keep their eyes from drying out. This is because they allow less light into their eye and are often made of materials that reduce friction on the eyeball, which can cause dryness.

14) They generally have a wider field of view which is excellent for people who wear glasses to see things at a distance, such as driving or watching television.

15) They don't need to be cleaned often because they have an anti-reflective coating that prevents smudges and makes it easier to clean them with water when necessary.

Reference:

• articlesbase.com
• bella-eyecare.com/eyeglasses/why-you-should-get-anti-reflective-lenses
• rx-able.com/blogs/blogs/benefits-and-disadvantages-of-anti-reflective-coating-glasses

Types of Lenses and Coatings

Single-vision lenses

The simplest form of spectacle or contact lens is the single-vision lens, made to a single prescription to correct a particular eyesight problem. Concave lenses are used to correct short sight and convex lenses to correct long sight. Concave lenses are generally thinner in the centre than they are at the edge and convex lenses are usually thinner at the edge than at the centre. The curvature of the lens, its thickness and weight will depend on the amount of long or short sight it is designed to correct. The lens material will also influence the thickness and weight of your lenses, as will the size and shape of the spectacle frame you choose. Traditionally, spectacle lenses were made of glass but most lenses are now lightweight plastic and there is a wide range of materials available to suit your prescription and lifestyle.

Bifocals

Bifocal lenses contain two optical corrections with a distinct dividing line between the two parts. The most common use of bifocals is for people who have become presbyopic and need a different prescription for close work. The upper part of the lens corrects distance vision and the lower half is for near vision. Trifocals are also available that have three sections and incorporate a correction for intermediate vision. Bifocals and trifocals come in a range of designs but nowadays varifocal lenses are much more likely to be prescribed.

Varifocal or progressive lenses

Varifocal lenses, also known as progressive lenses, are used for correcting presbyopia but unlike bifocal lenses have no visible dividing lines between the different corrections. Instead they have a graduated section in which the power of the lens progresses smoothly from one prescription to the other, allowing the wearer to see clearly at all distances. These lenses also have the benefit of looking better - they don't draw attention to the ageing process. A range of varifocal designs is available depending on your lifestyle and occupation. Modern lens technology means that there are many different designs and materials to choose from. Your optometrists or dispensing optician will be able to advise you on the best lenses to suit your individual requirements.

High-index and aspheric lenses

If you need high-powered lenses you can improve the weight or appearance of your glasses with special lens materials and designs. High-index materials and aspheric designs mean that lenses can now be made thinner, lighter and better looking than traditional lens types. High-index materials make lenses for short sight thinner, while aspheric designs that minimise the amount of material make lenses for long sight both thinner and lighter.

Prescription sunglasses

Whatever your prescription, it is important to protect the eyes against excessive ultraviolet (UV) radiation. Protection is needed to avoid reflected light from sand and snow or if you spend long periods out of doors, particularly in the summer. Prescription sunglasses can be made with single-vision, bifocal or varifocal designs to offer the same standard of protection as non-prescription sunglasses.

Safety and sports glasses

Special lenses and frames incorporating eye protection are available for a variety of safety and recreational uses.

Anti-reflection coating eResearch by Navid Ajamin -- winter 2010

Spectacle lenses can be provided with anti-reflection coatings which virtually eliminate distracting reflections off the lens surfaces. Reducing reflected light is particularly helpful for computer users and for night driving. Anti-reflection coatings also improve the cosmetic appearance of your glasses and can make thick lenses look thinner.

Scratch-resistant / hard coating

Plastic lenses are lighter than traditional glass lenses but they scratch more easily. Scratched lenses can be irritating for the wearer and look unsightly. Scratch-resistant coatings are available to protect against damage and prolong lens life.

Multi-coated lenses

Multi-coated lenses uncorporate a combination of coatings - anti-reflection, scratch-resistant, water repellent and UV - to combine to improve the properies of your spectacles.

Reference: college-optometrists.org

Anti-Reflection Coatings

AR coatings are similar to the coatings found on microscopes and camera lenses. They consist of several layers of metal oxides applied to the front and back lens surfaces. Because of the layering effect, AR coatings sometimes have a hint of green or purple color, depending on the individual manufacturer's formula.

The most important benefits of anti-reflective (AR) coating may be the unseen advantage--relief from fatigue and eyestrain caused by glare. AR does have a big cosmetic advantage, but removing the distracting reflections and ghost images that contribute to eyestrain clearly is a bigger benefit. This increases comfort. Being more comfortable in anything we do is a benefit, especially wearing glasses. People always remark how uncomfortable glasses are. Well now you can offer a real solution to that problem. AR Coating!!

Nighttime driving is also enhanced with AR coatings by eliminating the reflections from street lights, headlights from on-coming vehicles, and taillights. By applying an AR coating more light can pass through the lens providing greater image contrast and clearer vision.

Beyond these benefits and features, other ideal candidates are:

1. High Index Wearers-AR helps reduce the concentric rings these strong prescriptions produce.

2. Low Vision Patients-The increase of light transmission from AR coatings can benefit low vision patients.

3. Light-sensitive patients

4. Sunglass wearers

5. First time wearers of glasses

6. Professionals

7. VDT users can benefit from AR's ability to reduce glare.

You get more out of life when you can enjoy it longer. Vision problems such as glare, reflections, ghost images and the fatigue they create reduces your enjoyment. AR coatings improve vision, reduce fatigue, and help you to enjoy every minute of life at work or at play.

AR coatings enhance appearance. It makes lenses look thinner by reducing distracting reflections. Also the wearers eyes are more visible and this improves eye contact for better communication.

Now, we have mention the cosmetic and comfort features but there are more than that. AR lenses when worn in daylight and indoors, most people find it provides noticeable better visual performance, making objects appear crisper and brighter. When reading a newspaper, magazine, or even a computer screen with AR coated lenses images and letters will appear sharper and crisper. [1]

Anti-reflective eye glasses are designed to reduce glare on the lenses. This serves the dual purpose of improving the wearer’s vision and enhancing the appearance of the glasses themselves, particularly in photographs taken with a flash. eResearch by Navid Ajamin -- spring 2008

Composition

1. Anti-reflective coating consists of a series of layers of metal oxides. In the 1980s and 1990s, when anti-reflective lenses were relatively new, the coating was only a single layer that could easily become scratched or smudged.

Today, multiple layers enhance the properties of the anti-reflective coating, including oil-resistant, water-resistant, static-resistant and protective scratch-resistant layers.

Process

2. The process used to apply anti-reflective coating varies depending on the manufacturer. In some cases the coating is sprayed on in liquid form, then exposed to high heat so that the liquid solution hardens and adheres to the lens.

Another process coats each lens with a liquid and places it inside a vacuum chamber, where the vacuum process hardens the coating. In yet another process the anti-reflective coating is built into the material and distributed throughout.Care

3. Anti-reflective lenses require a little more care than regular lenses. They should not be cleaned with harsh chemicals, which can damage the anti-reflective coating. Additionally, they should be cleaned or rubbed only with a wet cloth, as a dry cloth can scratch the lens.[2]

Benefits of anti-reflective coating

Anti-reflective coating (also called “AR coating” or “anti-glare coating”) improves vision, reduces digital eye strain and makes your eyeglasses look more attractive. These benefits are due to the ability of AR coating to virtually eliminate reflections from the front and back surfaces of your eyeglass lenses.

With reflections gone, more light passes through your lenses to optimize visual acuity with fewer distractions (especially at night), and the lenses look nearly invisible — which enhances your appearance by drawing more attention to your eyes and helping you make better eye contact with others.

AR coating is especially beneficial when used on high-index lenses, which reflect more light than regular plastic lenses. Generally, the higher the index of refraction of the lens material, the more light that will be reflected from the surface of the lenses.

For example, regular plastic lenses reflect roughly 8% of light hitting the lenses, so only 92% of available light enters the eye for vision.

Photolithography

Antireflective coatings (ARC) are often used in microelectronic photolithography to help reduce image distortions associated with reflections off the surface of the substrate. Different types of antireflective coatings are applied either before (Bottom ARC, or BARC) or after the photoresist, and help reduce standing waves, thin-film interference, and specular reflections.

High index plastic lenses can reflect up to 50% more light than regular plastic lenses, so even less light is available to the eye for vision. This can be particularly troublesome in low-light conditions, such as when driving at night.

Today’s modern anti-reflective coatings can virtually eliminate the reflection of light from eyeglass lenses, allowing 99.5% of available light to pass through the lenses and enter the eye for good vision.

By eliminating reflections, AR coating also makes your eyeglass lenses look nearly invisible so people can see your eyes and facial expressions more clearly. Anti-reflective glasses also are more attractive, so you can look your best in all lighting conditions.

The visual benefits of lenses with anti-reflective coating include sharper vision with less glare when driving at night and greater comfort during prolonged computer use (compared with wearing eyeglass lenses without AR coating).

When applied to photochromic lenses, AR coating enhances the clarity and comfort of these premium lenses in all light conditions without reducing their sun-reactive performance.

Anti-reflective coating also is a good idea for sunglasses. It eliminates glare from sunlight reflecting into your eyes from the back surface of tinted lenses when the sun is behind you. (Generally, AR coating is applied only to the back surface of sunglass lenses because there are no cosmetic or visual benefits to eliminating reflections from the front surface of dark-tinted lenses.)

Most premium AR lenses include a surface treatment that seals the anti-reflective layers and makes the lenses easier to clean. These hydrophobic surface treatments also repel water, preventing the formation of water spots on your lenses.

Some anti-reflective lenses have surface treatments that are both hydrophobic and oleophobic (also called lipophobic), which means they repel both water and oil. These combination treatments typically contain fluorinated materials that give the lenses properties that are very similar to those of nonstick cookware.

Is anti-reflective the same as anti-glare?

Anti-reflective vs Anti Glare

In short: anti glare coatings will protect against external light sources entering the glasses, while anti-reflective coatings will protect against both internal and external light.

Anti Glare

To get into the physics of it, anti glare solutions equip glasses with diffusive properties which diffuse light that would usually be reflected off of the surface of your lens. This means that instead of producing specular reflection, it creates a diffuse reflection. Instead of the light ray reflecting directly off the lens, it is broken up into many weaker rays, meaning the reflection is far weaker or, often, unnoticeable. This means that anti glare coatings significantly reduce the amount of light that is reflected off the surface of the lens.

Anti-Reflective

On the other hand, anti-reflective lenses go a step further. These solutions use diffusive properties to diffuse both external and internal light. While “internal light” might sound strange, it refers to the small number of transitional light waves which are let loose as the light goes from one medium (in this case, air) into another (the lens). If unchecked, these small light rays can reflect within the lens itself, causing strange visual artefacts that lead to eye strain and discomfort. While these internal reflections may still be present in glasses with anti glare coatings, anti-reflective lenses go the extra mile to ensure the best user experience possible.

Anti-reflective coatings are often used in camera lenses, giving lens elements distinctive colors. Such colors indicate the wavelength of visible light least affected by the antireflective properties of the coating. A variety of colors can be produced whose precise hue depends entirely on the thickness of the coating.

Reference:

1. robertsonoptical.com
2. milenyumtasarim.com
3. en.wikipedia.org/wiki/Anti-reflective_coating
4. allaboutvision.com/lenses/anti-reflective.htm
5. rx-able.com/blogs/blogs/is-anti-reflective-the-same-as-anti-glare

See also:

• Disadvantages of Anti-Glare Coating

• My glasses have an anti-reflective coating. How does that work?