Snow blindness (photokeratitis)

Snow blindness is a painful but temporary form of vision loss caused by overexposure to reflected UV rays. The medical term for snow blindness is photokeratitis. Photo means light and keratitis is the inflammation of the cornea. Snow blindness is the result of your cornea being akin to sunburned. Photokeratitis is caused by damage to the eye from ultraviolet (UV) rays. Sunlight is the main source of natural UV rays [1]. However, unlike sunburn on your skin, by the time the symptoms of snow blindness appear, you’ve already been in the sun for too long.

Despite what the name suggests, you don’t need to be in the presence of snow to be affected by snow blindness. Snow itself can reflect more than 80 percent of UV rays. Extreme sports such as mountain climbing, snowboarding and skiing are done in high altitude where the sun UV’s rays are stronger and there is usually more snow, hence the term snow blindness has gained popularity. You can still get snow blindness at lower altitudes, although the risk is lower, almost half in fact.

Other sources of snow blindness can include UV rays off sunbeds or sparks from welding.

What are the symptoms of snow blindness (photokeratitis)?

Typical snow blindness symptoms include:

• Eye pain
• A burning sensation in the eyes
• Red eyes
• Sudden sensitivity to light
• Watering eyes
• Blurry vision
• Swollen eyes
• Swollen eyelids
• The feeling that there is something in your eyes

Preventing snow blindness

Prevention is always better than a treatment or cure and given how painful snow blindness can be, you definitely want to do everything you can to avoid getting it in the first place.

Here are some ways you can prevent snow blindness:

• Wear sunglasses with UV protection anytime you are out in the sun, especially if you’re around snow and water
• Make sure your glasses offer a minimum of 99% UV protection
• Stick to wrap-around sunglasses that offer maximum protection
• Opt for polarised sunglasses as they block intense reflected light
• If you’re in an area heavily covered with snow, avoid taking off your glasses until you’re inside

Treating snow blindness

Snow blindness is temporary and usually clears up by itself within a few days or sometimes even sooner. We suggest however, that you see a doctor as soon as possible to assess the extent of the damage.

To relieve any pain, we suggest the following:

• Painkillers can help subdue any feelings of discomfort. Make sure to take the recommended dosage and ensure that there are no interactions with any other medications you may be taking
• Avoid bright light and stay indoors
• Wear sunglasses during the day and a night mask when you go to sleep
• Keep your eyes moistened by using artificial tears. Stick to mild, preservative-free formulas that are gentle on the eyes and will not cause more irritation
• Dampening a cloth in warm water and placing it over your eyes may also provide temporary relief. We recommended you do this first thing in the morning and just before you go to sleep
• Avoid rubbing your eyes
• Avoid wearing contact lenses until the issue subsides
• Do not rub your eyes

[1] Porter, D. and Pagan-Duran MD, B. (2019). What is Photokeratitis — Including Snow Blindness?. [online] American Academy of Ophthalmology. Available at: https://www.aao.org/eye-health/diseases/photokeratitis-snow-blindness  [Accessed 21 May 2019].

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