In an environment of snow, ice, water, and sky, sunlight and its damaging ultraviolet rays strike you from every angle, and if you do not wear sunglasses, you will get snow blindness in very short order. In fact, you can get it just as quickly on cloudy days. Your eyes will become inflamed and painful, your eyelids will begin to smart, and you may get a headache. Most noticeably, you will suffer from photophobia, a painful sensitivity to bright light. If you're not careful, the condition can permanently damage your eyes.