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.