Just a few short hours in bright sunlight without sunglasses can expose your eyes to enough UV to cause a painful sunburn of the clear front surface of your eyes (cornea), called photokeratitis.
Commonly called snow blindness, photokeratitis causes severe eye pain, sensitivity to light and temporary loss of vision that can last up to 48 hours.
But you don't need to be around snow to get photokeratitis direct sunlight or sun combined with any substance that reflects a significant percentage of UV rays can cause sunburned eyes.
According to a May 2013 report by The Vision Council:
- Water reflects up to 100% of UV rays
- Snow reflects up to 85%
- Dry sand and concrete reflect up to 25%
- Even grass reflects up to 3%
For these reasons it's important to always wear proper sun protection for your eyes at all times when you're outdoors. This is especially true if your occupation requires you to spend much of your day outdoors or you simply like to spend as much leisure time as possible in the sun.
UV Map Index: See today's local UV levels.