Reasons to wear goggles:
-Sun reflects off of snow, causing what's called snow-blindness. If you are looking at the snow all day long without protection on a sunny day, prepare to have fried eyes for a while, not good.
-They protect against wind gusts, and also just simple wind-resistance created from moving fast. After getting wind blown in your eyes all day long, they are going to hurt, be dried out, and it will also suck while it's happening.
-Keeps snow/sleet out of your eyes when in adverse conditions.
-Allows you to see better in specific conditions, depends on the lense.
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