What is Snow Blindness?
What is Snow Blindness?
It is a beautiful, cloudless, bluebird day in the mountains. You take off your goggles during a lunch break to soak in the sun, and decide to ski the rest of the afternoon in just a hat.
Six hours later, you are sitting in your hotel room in agony, feeling like someone poured sand directly into your eyeballs.
You have Snow Blindness, and it is one of the most common—and entirely preventable—mountain injuries.
The Medical Reality: A Sunburn on Your Eyeball
Snow blindness (Photokeratitis) is literally a sunburn on the surface of your eye (the cornea and conjunctiva).
Why is it so common in the mountains? Two compounding factors create a devastating environment for your eyes:
- Altitude: For every 1,000 meters (3,280 ft) of elevation you gain, UV radiation intensity increases by 10%.
- Reflection: Fresh white snow is Nature’s mirror. It reflects up to 80% of UV rays straight back up at your face. Even if you are wearing a baseball cap, the UV light is blasting into your eyes from below.
Symptoms of Snow Blindness
The tricky part about photokeratitis is that, just like a skin sunburn, you rarely feel it while it is happening. Symptoms typically hit 6-12 hours after exposure.
- Intense pain and a gritty feeling (like sand in your eyes).
- Extreme sensitivity to light.
- Uncontrollable tearing and redness.
- Temporary vision loss or halo effects.
How to Treat It
If you suffer from snow blindness, do not rub your eyes.
- Go to a dark room immediately.
- Remove contact lenses.
- Apply a cold, damp cloth over your closed eyelids.
- Use artificial tear eye drops (avoid “redness relief” drops as they can irritate the burn further).
- Take over-the-counter pain relievers (Ibuprofen).
- Seek medical attention if the symptoms do not improve after 24 hours. A doctor may prescribe antibiotic drops to prevent infection.
Prevention: The Only Strategy
Prevention is simple: Never expose your naked eyes to the snow on a sunny day.
- Always wear Goggles or Sunglasses: Make sure your eyewear explicitly states it blocks 100% of UVA and UVB rays.
- Beware the “Cloudy Day” Myth: Up to 80% of UV rays can easily penetrate cloud cover. Even on a flat-light, overcast day, your eyes are still absorbing massive amounts of radiation bouncing off the snow. Keep your lenses on!