عینک eyewear

شب کوری برخلاف آنچه از اسمش برمی‌آید، ازدست‌دادن کامل بینایی در شب نیست، بلکه در افراد مبتلا به شب کوری توانایی دید در شب یا جاهای کم‌نور کمتر از حد معمول است. شب کوری برخلاف کوررنگی، به‌خودیِ خود اختلال نیست، بلکه نشانه‌ی بیماری دیگری است. شب کوری ممکن است در همه‌ی افراد و در همه‌ی سنین، حتی در کودکان رخ بدهد.

Night blindness (nyctalopia) occurs when a person has significant difficulty seeing in poorly lit environments. While it is relatively normal to experience some blurriness and trouble seeing clearly at night (due to a visual acuity issue), night blindness may be a warning sign of a serious eye condition.

There are two types of light-sensitive cells called rods and cones in the retina. The rods help us see in dim light while the cones enable us to see in brightly-lit settings. Nyctalopia is caused when the rods lose their ability to focus properly at night and under dim light

due to the following:

• Pre-existing health conditions such as cataracts, glaucoma, and diabetes
• A vitamin A-deficient diet
• Other causes may include medications used to treat glaucoma and a genetic disorder called retinitis pigmentosa.

Retina-related causes of night blindness include: Rare, genetic retinal diseases like cone-rod dystrophy, retinitis pigmentosa (also called rod-cone dystrophy, similar to but not the same as cone-rod dystrophy) or congenital stationary night blindness (CSNB).

بینایی در شب از جهات بسیاری با بینایی در روز متفاوت است. چشم انسان در تاریکی اصولا کوررنگ است، حدت بینایی ضعیف است و چشم تنها بخشی از آنچه را در روز می‌بیند، در شب هم می‌تواند ببیند. دلیل آن یک اسکوتوم مرکزی (ناحیه‌ای با کاهش دید) است که در مرکز میدان دید ظاهر می‌شود و بنابراین چشم نمی‌تواند آن‌طور که اشیای متحرک را شناسایی می‌کند، اشیای ایستا را نیز تشخیص بدهد.

اگر دیدتان در شب ضعیف است، اما طی روز یا در جایی که نور کافی دارد مشکلی ندارید و عادی می‌بینید، به احتمال زیاد به شب کوری دچارید. در این‌صورت نمی‌توانید اشیایی را که دیگران در شب به‌راحتی می‌بینند، ببینید و وقتی از محیط روشن به محیطی تاریک می‌روید، مثلا وارد سالن سینما می‌شوید، چشم‌هایتان برای سازگاری و تطابق با اطراف به زمان بیشتری نیاز دارد.

Hemeralopia (from Greek ημέρα, hemera "day"; and αλαός, alaos "blindness") is the inability to see clearly in bright light and is the exact opposite of nyctalopia (night blindness). Hemera was the Greek goddess of day and Nyx was the goddess of night. However, it has been used in an opposite sense by many non-English-speaking doctors. It can be described as insufficient adaptation to bright light. It is also called heliophobia and day blindness.

In hemeralopia, daytime vision gets worse, characterised by photoaversion (dislike/avoidance of light) rather than photophobia (eye discomfort/pain in light) which is typical of inflammations of eye. Nighttime vision largely remains unchanged due to the use of rods as opposed to cones (during the day), which are affected by hemeralopia and in turn degrade the daytime optical response. Hence many patients feel they see better at dusk than in daytime.

Causes

Hemeralopia is known to occur in several ocular conditions. Cone dystrophy and achromatopsia, affecting the cones in the retina, and the anti-epileptic drug Trimethadione are typical causes. Adie's pupil which fails to constrict in response to light; Aniridia, which is absence of the iris; Albinism where the iris is defectively pigmented may also cause this. Central Cataracts, due to the lens clouding, disperses the light before it can reach the retina, is a common cause of hemeralopia and photoaversion in elderly.

C.A.R (Cancer Associated Retinopathy) seen when certain cancers incite the production of deleterious antibodies against retinal components, may cause hemeralopia. Another known cause is a rare genetic condition called Cohen Syndrome (aka Pepper Syndrome). Cohen syndrome is mostly characterized by obesity, mental retardation, and craniofacial dysmorphism due to genetic mutation at locus 8q22-23. Rarely it may have ocular complications such as hemeralopia, pigmentary chorioretinitis, optic atrophy or retinal/iris coloboma, having a serious effect on the person's vision. Yet another cause of hemeralopia is uni- or bilateral postchiasmatic brain injury. This may also cause concomitant night blindness.

Management

People with hemeralopia may benefit from sunglasses. Wherever possible, environmental illumination should be adjusted to comfortable level. Light-filtering lenses appear to help in people reporting photophobia.Otherwise, treatment relies on identifying and treating any underlying disorder.

Nyctalopia /ˌnɪktəlˈoʊpiə/ (from Greek νύκτ-, nykt- "night"; ἀλαός, alaos "blind, not seeing", and ὄψ, ops "eye"), also called night-blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases.

Night blindness may exist from birth, or be caused by injury or malnutrition (for example, a lack of vitamin A). It can be described as insufficient adaptation to darkness. eResearch by Navid Ajamin -- summer 2013

The most common cause of nyctalopia is retinitis pigmentosa, a disorder in which the rod cells in the retina gradually lose their ability to respond to the light. Patients suffering from this genetic condition have progressive nyctalopia and eventually their daytime vision may also be affected. In X-linked congenital stationary night blindness, from birth the rods either do not work at all, or work very little, but the condition doesn't get worse. Another cause of night blindness is a deficiency of retinol, or vitamin A, found in fish oils, liver and dairy products.

The opposite problem, the inability to see in bright light, is known as hemeralopia and is much rarer.

What causes night blindness?

Night blindness has many causes, including:

• Myopia
• Glaucoma medications that work by constricting the pupil
• Cataracts
• Retinitis pigmentosa
• Vitamin A deficiency

To determine what is causing night blindness, an eye doctor will perform a thorough eye exam and may order any of a number of specialized exams.

How is night blindness treated?

Treatment for night blindness will depend upon its cause. Treatment may be as simple as getting a new eyeglass prescription or switching glaucoma medications, or it may require surgery if the night blindness is caused by cataracts.

If a retinal disease is discovered, the treatment will depend on the type of the disease and will require additional investigation by a retina specialist.

افرادی که به شب کوری دچارند، اغلب نمی‌توانند شب‌ها رانندگی کنند. اگر دیدتان در شب ضعیف است، حتما برای معاینه سری به چشم‌پزشک بزنید.

دلایل شب کوری

شب کوری (nyctalopia) یا ضعف سازگاری با تاریکی، به‌علت اختلال سلول‌هایی در شبکیه‌ی چشم است که مسئول دید در روشنایی اندک هستند. شب کوری ممکن است نشانه‌ی بیماری‌های مختلف اکتسابی یا مادرزادی باشد.

علت‌های اکتسابی

آب‌ مروارید (cataracts): افراد مبتلا به آب‌مروارید اغلب و به‌ویژه در شب نمی‌توانند به‌خوبی کتاب بخوانند، رانندگی کنند و حالت‌های چهره‌ را تشخیص بدهند.
نزدیک‌بینی (myopia): گاهی علت شب کوری، نزدیک‌بینی درمان‌نشده است.
مصرف بعضی داروها: بعضی داروهای آب‌سیاه یا گلوکوم (glaucoma) مردمک چشم را ضعیف و دید در شب را با مشکل مواجه می‌کنند.
کمبود ویتامین A: شب کوری یکی از اولین نشانه‌های کمبود ویتامین A است که معمولا با سوء‌تغذیه در ارتباط است. کمبود ویتامین اغلب در کودکانی رخ می‌دهد که دچار سوء‌تغذیه هستند. این کودکان آن‌قدر کم‌سن‌وسال هستند که نمی‌توانند مشکل دیدشان در شب را تشخیص بدهند یا مشکل بینایی خود را بازگو کنند.

علت‌های مادرزادی

شب کوری مادرزادی، با یا بدون نزدیک‌بینی: این مورد به گروهی از اختلالات ناهمگن ژنتیکی (جهش ژنتیکی) برمی‌گردد. نوعی از شب کوری مادرزادی (choroideremia) فقط روی جنس مذکر اثر می‌گذارد؛ جنس مؤنث حامل ژن‌های مربوطه است، اما نشانه‌های این بیماری را ندارد؛
رتینیت پیگمنتوزا (Retinitis pigmentosa): این بیماری چشمی درنتیجه‌ی چندین نقص چشمی اتفاق می‌افتد که منجر به آسیب شبکیه می‌شوند. افراد مبتلا ممکن است در شب یا روشنایی کم، کاهش دید داشته باشند؛ حتی ممکن است در دید میانی و جانبی نیز مشکل داشته باشند. نشانه‌های این بیماری در دوران کودکی قابل شناسایی هستند، اما اغلب در بزرگسالی آشکار می‌شوند.
سندرم آشر (Usher syndrome): این سندرم با کاهش شنوایی و رتینیت پیگمنتوزا شناخته می‌شود و همان‌طور که قبلا گفتیم ممکن است باعث شب کوری شود.

آزمایش شب کوری

اگر شب‌ها نمی‌توانید به‌خوبی ببینید، باید به چشم‌پزشک مراجعه کنید. در چنین مواردی، چشم‌پزشک آزمایش‌هایی انجام می‌دهد تا مشخص شود آیا به شب کوری مبتلا هستید یا نه، و آیا این شب کوری به بیماری دیگری ارتباط دارد یا خیر.

معاینه‌ی چشم شامل موارد زیر است:

• آزمایش‌هایی برای بررسی حدت بینایی
• توانایی تشخیص رنگ‌ها و واکنش مردمک چشم به روشنایی
• آزمایش انکسار برای بررسی تجویز عینک یا لنز چشم
• معاینه‌ی لامپ اسلیت برای بررسی ساختارهای جلوی چشم ازجمله ملتحمه، قرنیه، پلک‌ها، عنبیه، عدسی‌ها و صلبیه؛
• معاینه‌ی شبکیه برای بررسی وجود هرگونه آسیب در ساختارهای پشت چشم ازجمله زجاجیه، شبکیه و مشیمیه.

ممکن است چشم‌پزشک الکترورتینوگرافی (Electroretinography) تجویز کند. این آزمایش واکنش‌های الکتریکیِ سلول‌های استوانه‌ای‌ و مخروطی‌ (سلول‌های گیرنده‌ی نور) را در معرض نور بررسی می‌کند و می‌تواند عملکرد غیرطبیعی شبکیه، یعنی بخش تشخیص نور چشم را شناسایی کند.

ممکن است آزمایش میدان دید هم روی فرد انجام شود. این آزمایش مشکلات دید میانی و جانبی را که بر اثر گلوکوم و دیگر بیماری‌های چشمی یا به‌واسطه‌ی مسائلی هم‌چون سکته‌ی مغزی ایجاد شده‌اند، تشخیص می‌دهد.

درمان شب کوری

اگر شب کوری بر اثر بیماری دیگری به‌وجود آمده باشد، معمولا بعد از درمان آن بیماری برطرف می‌شود. آب‌مروارید معمولا با جراحی درمان می‌شود و نزدیک‌بینی با تجویز عینک یا لنز بهبود می‌یابد.

در افراد مبتلا به آب‌سیاه یا گلوکوم، استفاده از داروهای مناسب ممکن است از شدت بیماری بکاهد. افرادی که کمبود ویتامین A دارند، معمولا به مکمل‌های غذایی و رژیم غذایی سالم واکنش خوبی نشان می‌دهند. درمان زودهنگام کمبود ویتامین A بسیار مهم است زیرا اگر بدون توجه رها شود، به کوری دائم منجر خواهد شد.

اگر شب کوری ناشی از اختلال مادرزادی باشد، دائمی است و افرادی که از این طریق دچار آسیب شده‌اند باید تحت نظر چشم‌پزشک باشند. این افراد باید بیشتر احتیاط کنند تا از آسیب‌هایی که ممکن است بر اثر دید ضعیف در شب به‌وجود بیایند، در امان بمانند.

برای درمان شب کوری، باید به‌طور منظم تحت نظر چشم‌پزشک باشید. شاید برای رانندگی در شب به عینک نیاز داشته باشید. برای کاهش خطر آسیب به خود و دیگران هنگام فعالیت‌های شبانه‌ هم‌چون رانندگی، تشخیص زودهنگام این بیماری بسیار اهمیت دارد.

Vitamin A, also known as retinol, is a nutrient that plays an essential role in the function of your retina. The retina is located in the back of your eye and is responsible for image processing. Without enough vitamin A in your body, your retina can’t work as well as it should. A Vitamin A deficiency is often the cause of diet or underlying health conditions. Luckily, plenty of foods are rich in vitamin A, such as kale, seaweed, carrots, fish oils, dairy, and much more.

Although incorporating vitamin A-rich foods into your diet is a great way to promote the longevity of your eye health, you should always tell your eye doctor if you’re experiencing any changes in your vision.

Zinc Deficiency

Zinc is an essential nutrient for eye health and retina function as well. This important mineral can even help prevent eye diseases like macular degeneration. However, when your body doesn’t get enough zinc, this can cause vision problems such as night blindness.

A great way to increase your zinc intake naturally is through your diet. Meats, shellfish, dairy, eggs, and legumes are all excellent sources of zinc.

پیشگیری از آسیب ناشی از شب کوری
رانندگی در شب برای این بیماران خطرناک است، زیرا سرعت واکنش راننده هنگام رانندگی به دید او بستگی دارد. حتی دید طبیعی در شب بسیار محدودتر از روز است. رانندگان مسن‌ در مقایسه با جوان‌ترها، هنگام رانندگی در شب دید کمتری دارند. برای مثال راننده‌ی پنجاه ساله، به نوری دوبرابرِ راننده‌ی سی ساله نیاز دارد.

بهترین راهِ محافظت از خودتان در برابر آسیب‌های ناشی از شب کوری، اجتناب از رانندگی در شب است. سعی کنید صرفا در طول روز رانندگی کنید. کسانی که به شب کوری دچارند ممکن است حتی زیر نورهای مصنوعی هم با مشکل مواجه شوند. اگر واجب است شب‌ها رانندگی کنید، نکاتی را برای ایمنی بیشتر رعایت کنید. مثلا با تمیز کردنِ شیشه‌ها و چراغ‌های جلوی خودرو، دید خود را افزایش بدهید؛ با سرعت کمتری رانندگی کنید تا در صورت بروز اتفاقات غیرمنتظره، بتوانید سریع‌تر واکنش نشان بدهید.

Reference:

• my.clevelandclinic.org/health/symptoms/10118-night-blindness-nyctalopia
• millervision2020.com/trouble-seeing-at-night-all-about-night-blindness
• heinfolist.com/php/SummaryGet.php?FindGo=hemeralopia
• neovisioneyecenters.com
• researchgate.net/figure
• clevelandclinic.org
• chetor.com/119356
• en.wikipedia.org
• retinasocal.com

A 5-Minute Safety Training Aid

You are driving on a dark twolane road. An on coming vehicle’s high beams suddenly appear. The vehicle flashes past and for the next few seconds, you’re blind. You’ve just experienced a common hazard known as night blindness.

Night blindness occurs when the eye is accustomed to low levels of light and the light intensity
suddenly rises. The eyes adjust to the new light level by contracting the pupils, but if that level of intensity is only momentary, then the eyes have to readjust to the lower level again by dilating the pupil.

While the eyes make these adjustments, there are several seconds that the vision is impaired.

During the day about 85 percent of the information we need to drive is visual, but at night this changes. Without enough light, we lose much of our contrast sensitivity (the ability to distinguish objects from the background) and peripheral vision (the ability to recognize objects at the edges of our visual field).

At night, headlights limit our visual range to the area they illuminate, only 250 to 350 feet of the road ahead.

At sixty miles per hour a car will cover 350 feet in four seconds. Therefore, slower driving speeds will allow you more time to spot a hazard and respond in a crisis.
With this in mind, pedestrians should wear light-colored clothing or put reflective tape on their clothes to make themselves more visible in the darkness.

If a driver turns his or her head from side to side, it will help make up for the lost side vision that occurs at night.

Also, if the driver must wear glasses to drive, frames that have thin sidepieces should be selected, since wide sidepieces will hinder side vision.

In addition to the problems listed above, there is the fact that as we age the lenses of our eyes become yellowed and we need more light to see. Most of us begin to notice this in our 40’s. By the age of 65 we need 2.5 times the light that we needed when we were 20 to see the same level of detail. For this reason, older persons should drive slower when they find it necessary to drive at night. Whatever your age, precautions must be taken to avoid accidents.

The following traffic safety do's and don’ts may help.

Do eResearch by Navid Ajamin -- spring 2013
+ Drive within the range of your headlights, not by what you think you see beyond your headlights.• + Adjust your rear view mirror to the “night” setting to dim headlight glare coming from behind. When the glare is gone, readjust to the “day” setting.
+ Focus your eyes on the right edge of the pavement to avoid being blinded by oncoming headlights.• + Clean your headlights.
+ Clean your windshield (inside and out).

+ Keep your eyes moving between the road and the rear and side-view mirrors.
+ Use your high beams when you can.• Take off sunglasses at dusk.
+ Turn your head from side to side to increase your peripheral vision.

+ Dim your instrument lights to reduce brightness when you look at them.

Don’t
• Drive faster than sixty-five miles per hour at night, slower on winding roads.• Put dark aftermarket tinting film on windows and windshields.
• Depend on fog or parking lights when driving at dusk or dawn.• Keep your high beams on when another vehicle approaches.
• Exceed the speed for driving conditions at night in rain, snow or fog.• Turn your interior lights on while driving your vehicle.
• Wear sunglasses at night.• Stare into your side-view mirrors as cars pass from behind.
• Use any type of medication that may change your night vision or cause drowsiness.[1]

Night blindness doesn’t mean you are completely unable to see at night, but that your vision is poorer then. It is not a disease in itself, but instead is a symptom of some other type of vision problem.

In some cases, being very nearsighted (myopic) can make it hard to see at night or in low light.

Certain cells in the eye’s retina are responsible for allowing you to see in dim light. If these cells are affected by a disease or condition, night blindness occurs.

Some of the eye conditions that can cause night blindness include:

• Nearsightedness (seeing well up close but not far away)
• Glaucoma (a disease of the optic nerve connecting the eye to the brain)
• Medicine for glaucoma that constricts (narrows) the pupil
• Cataracts (cloudiness of the eye’s naturally clear lens)
• Diabetes (uncontrolled blood sugar levels)
• Retinitis pigmentosa (an eye disease that causes blindness)
• Too little Vitamin A
• Keratoconus (having a cornea that is very steeply curved)

Is bumping and tripping through your darkened house normal or a symptom of something else?

If you aren’t sure whether you have night blindness, consider the following questions:

• Do you find yourself having trouble moving around your house at night, even with small night lights?
• Is driving at night becoming more difficult?
• Do you avoid going outside at night for fear of tripping?
• Do you have trouble recognizing people’s faces in darkened settings?
• Does it take your eyes a long time to adjust to light when coming in from the darkness?
• Similarly, does it take you a long time to adjust to seeing anything in a darkened room?

If you have any concerns about your ability to see in the dark or in dim light, speak with your ophthalmologist right away. Having a complete eye exam will help identify any condition affecting your vision.

Treating night blindness depends solely on its cause. If your refractive error is significant, getting a new prescription for your eyeglasses may be all you need for better vision in low light. In some cases, having cataracts removed can be illuminating as far as your vision is concerned. Your ophthalmologist can explain what is causing your night blindness and suggest how to brighten your outlook.[2]

Humans are not designed to be creatures of the night, so remember to respect the road and the darkness.

The Fédération Internationale de l'Automobile (FIA) created the Golden Rules for Road Safety as guidelines for drivers to keep themselves and other road users safer in transit. To start: Check your vision regularly, protect your eyes from glare and always wear your glasses on the road. The FIA also advises that motorists: [3]

• Always pay attention
• Obey the speed limit
• Buckle up
• Use a child safety seat
• Check their tyres
• Don't text and drive
• Stay bright in reflective gear
• Wear a helmet
• Stop when they're tired
• Watch out for pedestrians, especially kids
• Slow down for kids
• Never drink and drive

Reference:

1. tdi.texas.gov
2. aao.org/eye-health/news/shedding-light-on-night-blindness
3. essilor.com/ie-en/blog/your-life-and-your-eyes/cannot-see-when-driving-at-night

drivewear® is a brand that has developed prescription lenses specifically for driving. it is the only photochromic lens to darken behind the windshield of a car or motorcycle visor by featuring unique photochromic dyes which respond to visible light in addition to uv light. the lens also incorporates a polarized filter to reduce glare at all light levels. this makes it uniquely flexible for driving throughout the year in a wide range of daylight conditions. their lenses combine two of the most advanced technologies in the eyeglass industry today – transitions® photochromic technology and nupolar® polarization.

What color lenses are best for night driving?

Driving can cause a strain on your eyes especially at night because of the lights of oncoming traffic. So what is considered the best lens color for night driving…well, there are 2 options; either a clear lens with an AR (anti-reflective) coating or a yellow lens with an AR coating.

The ideal driving glasses provide effective protection against glare with an appropriate anti-reflective coating and polarised or tinted lenses for presbyopia, progressive lenses should accommodate typical shifts in focus while driving.

Daylight driving
Copper – Variable Colour

The lens darkens or lightens to a copper colour providing excellent traffic signal recognition, greater depth perception and enhanced contrast for ultimate visual quality and safety. The polarization blocks dangerous blinding glare. Lens darkens up to 75% tint.

how do drivewear® lenses work?

in virtually every daylight driving situation, drivewear lenses provide optimal visual comfort and safety. they do this by changing colour in response to changing light conditions.

in low light, the lenses are a green/yellow colour which provides high contrast. this colour is designed to minimize glare and maximize useful light information reaching the eye for optimum visual acuity.

in daylight, (behind the windshield of a car) they change to a copper colour, which reduces glare and excess visual light. this colour provides good traffic signal recognition, highlighting reds and greens and provides best overall vision for driving in this environment.

in outdoor light, they become a dark reddish-brown colour, providing maximum comfort in high ght conditions by filtering excess light.

drivewear lenses also utilize nupolar (the same prescription lenses used by eyekit.co) the world’s leading polarized rx technology, to provide protection from blinding glare. only polarized lenses can do this.

drivewear is designed to provide maximum comfort to the wearer in most daylight conditions. they also block 100% of uva and uvb rays protecting the eye from potential eye disorders caused by uv radiation.

can i have a mirror coat on my drivewear lenses?

mirror coatings are not recommended since mirrors reflect the visible light and will not allow visible light photochromic activation. as such, we do not offer drivewear prescription mirror lens packages. eResearch by navid ajamin -- spring 2013

can i tint drivewear lenses?

tinting is not recommended as the product darkens considerably outside. additional tint could reduce outdoor transmission to possibly dangerous levels. as such, we do not offer drivewear prescription tint lens packages.

can drivewear be used for night driving?

drivewear lenses are optimized for sunlight response. they should not be used for night driving. many vision & highway safety experts believe that no tint should ever be used at night.

Good driving vision is influenced by a combination of factors

The following visual aspects are important to make safe driving decisions:

• You have to be able to see without glare and reflections during the day, but also clearly and with contrast at night. Your eye care professional can assist you in selecting anti-glare sunglasses or distance glasses for driving.
• Your vision shouldn’t be obstructed. Keep this in mind when you select your spectacle frames and prescription sunglasses frames. Frames that don’t fit properly can slip and move, blocking parts of your field of vision.
• You must be able to focus on close objects. As mentioned above, from age 40 onwards drivers may start to suffer from the onset of presbyopia which gradually causes vision to deteriorate.

The right spectacle lenses and well-fitted spectacle frames will be the solution to every one of these vision requirements. Remember to discuss your visual needs with your eye care professional when you go for an eye test. Give them as much background information as possible and mention whether you drive frequently, or experience any problems when night-driving. This way, they will be able to take everything into consideration and prepare the best possible prescription driving glasses.

Reference:

• eyekit.co
• drivewear.com
• blueberryglasses.uk/product/night-drive-l
• vseyewear.com/2023/02/what-color-clip-on-lens-is-best-for-night-driving
• zeiss.com/vision-care/en/eye-health-and-care/driving-mobility/the-best-glasses-for-driving.html

See also:

• 6 tips for safe driving in the dark

Polarized sunglasses are sunglasses that help diminish the glare of the sun. Polarized sunglasses provide incredibly clear, glare-free vision. These glasses were first worn by pilots to help them see when the sun was shining in different spots during the day. These days, many people wear polarized sunglasses when driving, golfing, and fishing. They look the same of other types of sunglasses, but deflect the sunlight in such a way so that it is not distracting when they are focusing on other things.

This causes the dramatic reduction in glare and increases visibility.

For those who drive a great deal during the day, these sunglasses will help keep the sun from becoming too distracting and help prevent squinting.

eople seem to get less tired, suffer less fatigue, and have fewer headaches on long trips.

Polarized sunglasses can make driving a boat or a car safer and improve outdoor sports performances.

When fishing, wearing polarized sunglasses will allow people to see into the water more clearly and accurately. When the sun is out, it can reflect off the water and cause the visibility to go down. When fishing, many people need to see into the water. Polarized sunglasses take a lot of the glare off the water allowing people to see what is below. This is helpful when boating also. In order to protect the boat from jagged rocks just below the surface, people can navigate the boat around these objects because they saw them ahead of time. These sunglasses can cave people from a wide variety of accidents both in the water and on the road.

Polarized sunglasses are not too expensive and come in a wide variety of styles and colors. They can be found wherever sunglasses are sold. At first, many of these sunglasses came with yellow tinted lenses, but these days the lenses are clear which many people are happy about. For those who enjoy outdoor activities like hiking, hunting, and sports, a pair of these sunglasses will help them get the most out of their day. Buying a pair of these sunglasses will help a person enjoy being out in the sun and not having to worry about missing out on any part of it.

Polarized sunglasses are so lightweight; you'll almost forget you're wearing them. They also provide excellent coverage and protection from wind, glare, and dust. Though they cost a little more initially, the increase in vision is dramatic. They are well worth the investment, especially if they prevent just one accident. eResearch by navid ajamin -- summer 2008

When Should You Wear Polarized Sunglasses?

Glare can be dangerous, especially when driving because it distorts the true color of objects and makes objects harder to see. Glare has been linked to many pedestrian deaths and traffic accidents.

Polarized sunglasses can be especially helpful in situations like:

• Driving: This is especially true on extremely hot days when the combination of hot air near the surface of a road and less hot air above it causes a mirroring effect.
• Playing outdoor sports: Polarized sunglasses help athletes see with greater clarity so that they can safely maneuver while competing in full daylight.
• Water activities: This includes speedboating, sailing, fishing, and other water sports when glare can come from all directions as sunlight bounces off waves or moving water.

How Polarized Lenses Enhance Color and Clarity?

The polarization of the lenses helps to reduce glare, which in turn enhances color and clarity. The chemical treatment used in polarized lenses blocks out certain wavelengths of light, leaving other wavelengths unchanged. This reduces the light entering your eyes and makes colors appear more vivid and clear.

The color of the lens can also affect color perception and clarity. Different colors are better for different conditions, so it’s important to pick the right lenses for your needs.

Benefits of Improved Color Perception and Clarity

Some of the benefits of improved color perception and clarity provided by polarized lenses include:

Enhanced detail

You’ll be able to see details more clearly and accurately, making activities like photography or painting easier.

Vivid colors

Colors will appear sharper and more vibrant due to the reduced glare. This can make outdoor activities such as hiking or bird watching much more enjoyable.

Improved depth perception

Polarized lenses help create a three-dimensional effect, allowing you to perceive depth and distance better. This can be especially helpful for activities like golfing or skiing, where accuracy is important.

Protection from Harmful UV Rays

Polarized lenses also protect from harmful UV rays. These lenses are designed to block out UVA and UVB radiation, which can harm your eyes over time. This is especially important in skiing or hiking, where the sun’s rays can be strong.

How Polarized Lenses Block Harmful UV Rays?

Polarized lenses are treated with a special chemical that helps block UVA and UVB radiation. This treatment allows the lenses to filter out certain wavelengths of light while still allowing other wavelengths through. This reduces the amount of harmful rays entering your eyes and keeps them safe from long-term damage.

Benefits of Blocking Harmful UV Rays

The benefits of blocking harmful UV rays are numerous,

including:

Protection from long-term damage

The reduced amount of UV radiation entering your eyes helps to protect them from long-term damage. This can help you maintain a healthy vision for years to come.

Reduced eye strain and fatigue

Blocking UV radiation can also help to reduce eye strain and fatigue, which is especially beneficial during activities like skiing or golfing.

Long-term health benefits

In addition to providing eye protection, blocking out UV radiation can also help to reduce the risk of skin cancer and other diseases.

Polarised Sunglasses vs Normal Sunglasses:

Normal sunglasses offer basic protection against bright light & UV rays but only polarised lenses block blinding glare and can also enhance visual acuity, colour contrast and visual comfort, blocking 100% of harmful UVA/B light.

Different Types Of Polarised Lenses:

Lenses can be polarised to different degrees and in different ways. Most inexpensive polarised sunglasses have a thin film applied on one side of the lens. Many higher quality lenses have film laminated between two layers of lens material, preventing it from being scratched or rubbed off. In addition, the more dense the film is, the more polarisation it provides.

In most cases, polarised sunglasses don't look any different from regular sunglasses. While denser films tend to be darker, the colour of a lens does not determine how much polarization it provides.

A very dark pair of sunglasses with a light film will not block more glare than a lighter shade of glasses with a denser film. The colour of the lens is also variable; although they cannot be made clear, polarised lenses can be made in grey, brown, green, or other colours.

The Benefits of Polarized Lenses for Children

These lenses help reduce glare from reflective surfaces, improving visual clarity and reducing eye strain. This enhanced vision can improve safety in sports by allowing children to see more clearly and react more quickly to their surroundings.

How to Protect Your Child's Vision Outdoors

As parents, you want the best for your child, including their vision. Here are some tips to help keep their eyes safe during outdoor activities and sports this summer:

• Wear Protective Eyewear: Ensure children wear protective eyewear with UV protection, such as sunglasses with polarized lenses or sports goggles, to shield their eyes from harmful UV rays and potential injuries.
• Use Hats and Visors: Encourage children to wear hats or visors to reduce UV exposure and protect their eyes from direct sunlight.
• Choose the Right Gear: Invest in sport-specific protective eyewear that meets safety standards to protect against impact and debris for specific sports.
• Educate About Safety: Teach children the importance of eye safety, including avoiding direct sunlight exposure and the risks of rubbing their eyes with dirty hands, which can lead to infections.
• Regular Eye Exams: Maintain regular eye check-ups to monitor their eye health and update prescription lenses as needed, ensuring optimal vision.

Reference:

• streetdirectory.com
• verywellhealth.com/polarized-sunglasses-3422163
• popularmechanics.com/science/a28191/polarized-sunglasses-bells-theorem
• danielwalters.com/blog/benefits-of-polarized-lenses-why-theyre-worth-investing-in
• bethesdavisioncare.com/why-polarized-lenses-are-a-game-changer-in-kids-sports