Chances are, you’ve heard plenty about the dangers UV radiation poses to your skin, even in wintertime. Here’s something you may not have heard: UV radiation actually can burn your eyes.

“Snow blindness,” also called photokeratitis [pho•to•ker•a•ti•tis], is a burn of the cornea, the eye’s outer layer. According to the Environmental Protection Agency, people typically get it from spending lots of time without adequate eye protection in settings where UV radiation from the sun reflects off snow, water or concrete.

Snow is the most reflective of these substances, hence the condition’s nickname. Tanning beds, welding tools and other artificial sources of UV radiation can be culprits, too.

If you think a sunburn on your eye sounds pretty unpleasant, you’re right. A burned cornea can make your eye feel like it’s full of grit, a sensation you just can’t shake. Other symptoms include sensitivity to light, pain and increased tear production. That’s enough discomfort to ruin even the best ski vacation.

How does one prevent snow blindness? Protect your eyes with sunglasses or ski goggles specifically designed to guard against UV radiation. Add a hat with a wide brim, and even less radiation will reach your peepers.

Animals who live in arctic regions have something even better than glasses and hats. Reindeer, for example, can see some types of UV radiation and aren’t susceptible to snow blindness. Their ability to process UV radiation is key in their habitat, where the sun’s low position on the horizon makes for higher than normal levels of the stuff.

And their eyes’ natural protection from UV radiation must come in handy when the reindeer are guiding Santa’s sleigh back to the North Pole just as day breaks. We’re guessing a team of flying reindeer suffering from snow blindness wouldn’t be much help to Old Saint Nick.