Prevention, Symptoms and Treatment for Snow Blindness

What winter sports and activities enthusiasts should know about snow blindness

Male snowboarder looking over Chamonix, Mont Blanc
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Snow blindness, or photokeratitis, is a painful eye condition caused by too much exposure to the sun’s UV rays. Those most at risk for snow blindness are those traveling outside in snowy terrain, across a snowfield or in a high-altitude winter environment, without proper eye protection. Prevent snow blindness by choosing sunglasses, glacier goggles or snow goggles that effectively block out the sun’s UV rays from all angles.

Snow blindness doesn’t only affect those who live in the polar regions: it can also affect anyone who enjoys snowy outdoor activities such as hiking, snowshoeing or skiing. In these conditions, the sun’s ultraviolet rays can burn the cornea of the eye, causing snow blindness that may not be noticed until several hours after intense sun exposure.

Symptoms of Snow Blindness

Symptoms of snow blindness may include increased tearing or watering of the eyes, bloodshot eyes, uncontrollable eyelid twitching, headache, hazy vision, halos around lights, and eye pain. The most common symptom is a feeling of sand or grit in the eyes. The eyes may swell shut in extreme cases. The pain caused by snow blindness is a result of the cornea’s inflammation, which occurs when the cornea is exposed to the sun’s UV rays, either through lack of eye protection or eye protection that is inadequate for the conditions. Snow blindness may cause a temporary loss of vision or even permanent vision loss in extreme cases of repeated exposure.

Snow blindness will likely affect those traveling in snowy conditions who are not wearing any eye protection, but it can also affect those who are wearing inadequate eye protection, such as sunglasses that allow light to enter the sides or sunglasses that don’t block out enough of the sun’s rays. Even some types of snow goggles may not offer enough protection against the sun’s UV rays, especially when the sun is intense and when snow and ice cover the ground, such as on a glacier or in a snow-covered high alpine environment.

Tips for Prevention

Sunglasses: Choose sunglasses that effectively block out the sun’s UV rays from all possible reflective surfaces. If you are traveling in the conditions that can cause snow blindness, you will likely need full-coverage or wrap-style sunglasses that prevent light from entering at the sides. Choose polarized or dark, mirror-coated sunglasses for the best results.

Glacier goggles: If you have trouble finding sunglasses that offer full coverage, look specifically for glacier goggles, or glacier sunglasses, which fit like sunglasses but often have extra features to block out the light--such as plastic or other material attachments on the sides and lower portions of the glasses. Glacier goggles often have mirrored, polarized lenses that are darker than regular sunglasses. If you lose your eye protection in a snowy environment, know how to make your own improvised snow goggles from common outdoor gear or resources in your natural surroundings.

Snow goggles: Snow goggles, otherwise known as ski goggles, will work well for those traveling in snowy conditions, especially when it becomes windy or blizzard-like. Snow goggles are tight-fitting and offer full eye coverage, but you still need to choose a dark or mirrored lens, especially if you anticipate traveling in sunny conditions for an extended time over a glacier or snowfield.

How to Treat Snow Blindness

Treatment consists mainly of keeping the eye closed with patches.

If any of the symptoms of snow blindness are present, remove yourself immediately from the injury source--the sunlight and its reflective surface. Go inside, if possible, and rest in a dark room, or rest in your tent with a dark cloth covering your eyes. If you wear contact lenses, remove them, and do not rub your eyes.

Seek medical attention if pain persists, as eye drops may be prescribed to ease the pain and aid healing. If you are unable to see a doctor, apply a cool compress to your eyes to ease the pain. Healing may occur in one to three days if you remain isolated from the injury source. You may speed up the healing process by covering your eyes with eye pads, gauze bandages or other improvised material to block all light from entering your eyes.

A doctor may recommend may prescribe an ophthalmic antibiotic solution, such as sulfacetamide sodium 10% with methylcellulose or gentamicin, as an eye drop treatment. In severe cases, vision usually returns after 18 hours, and the surface of the cornea usually regenerates in 24 to 48 hours.