We’ve all heard that we’re supposed to wear sunscreen to prevent sunburn.
But did you know that you can actually sunburn your eyes? It’s called photokeratitis, and it’s from the same source as a traditional skin sunburn—overexposure to harmful UV rays.
Unlike your back or shoulders that are usually covered by clothes, however, your eyes are always exposed to the elements, including ultraviolet rays.
Also unlike sunburning your skin, you don’t have to be at the beach to develop it.
In fact, a common cause of corneal photokeratitis is spending the day on the ski slopes.
That’s why this condition is sometimes called “snow blindness.”
The sunburn happens to the cornea—the clear layer that covers the front of your eye—and the conjunctiva—an even thinner layer that covers both the whites of the eye and the inner surface of the eyelid.
Snow blindness can also include the freezing of these delicate layers, as well as severe drying of the surface tissues.
Snow is so dangerous to the eyes because of how reflective it can be.
Snow reflects both visible light and ultraviolet rays—up to 80 percent of UV.
High altitude can also play a role.
Ultraviolet rays are stronger in higher climes where there is less atmosphere to filter them out.
Many winter activities, such as mountain climbing, snowmobiling, snowshoeing, skiing, and snowboarding, often take place in higher altitudes.
The elevation and the reflective snow put together can as much as double your risk of photokeratitis.
Not all cases of snow blindness are associated with snow.
Open water in lakes, rivers, and oceans can be just as reflective.
A few years ago, cable news journalist Anderson Cooper experienced 36 hours of temporary blindness after spending too much time on the open water for a story in Portugal.
UV-blocking sunglasses are a must for boating and recreational activities on the water, where the surface of a lake or sea is also highly reflective and adds extra UV exposure.
In addition, photokeratitis can also be caused by made-made sources, such as tanning beds and arc welding.
If you’ve been outside on the water or ice, be careful.
Just as with sunburn to the skin, once you notice something wrong with your eyes, it’s already too late to prevent most of the damage.
Be aware of these warning signs from the American Academy of Ophthalmology that you’ve overexposed your eyes:
- Eye pain and swelling
- Redness, irritation, or gritty feeling in your eyes
- Blurry vision
- Sensitivity to bright light with or without tearing
- Seeing halos around objects
- Decreased pupil size
- Twitching of eyelids
- Sunburn to the skin surrounding your eyes
- Temporary vision loss
Read the American Academy of Ophthalmology’s full recommendations for preventing snow blindness.
They describe the condition and what kind of sunglasses to look for exactly.
For example, “There is presently no uniform labeling of sunglasses that provides adequate information to the consumer. Labels should be examined carefully to ensure that the lenses purchased absorb at least 99-100% of both UV-B and UV-A.”
Our team at Bard Optical can help you sort out their recommendations and help you find a product that fits your lifestyle, whether or not you have a prescription.