Even on a cloudy day, ultraviolet light is intense on high-elevation ski slopes and snowshoe trails.
And in bright light, with the sun reflecting off the snow, it doesn't take much to get ultraviolet keratitis, commonly known as snow blindness.
It's like a sunburn of the cornea. You don't notice it until several hours after exposure when you tear up at the painful, gritty way your eyes feel.
The only way to avoid this is by using sunglasses or ski goggles.
Andy Boos, who takes people up into the mountains on snowshoe journeys hosted by Everett Parks and Recreation, believes ski goggles are best. They don't fall off and they offer the best protection, Boos said.
For very active cross-country skiers and snowshoers, Tristan Louden at REI suggests sunglasses rated for UV protection.
"For people who sweat, goggles fog up too easily," Louden said. "It's fine just to get good, polarized sunglasses."
Sunscreen protection also is a must for those outdoors during the winter, Louden said.
"No matter if your cap is pulled low or your turtleneck pulled high, a zinc oxide sunscreen is a good idea," he said.
A popular brand available at places such as REI and Cabela's is Sawyer Stay-Put SPF 50 sunscreen lotion for winter sports and high altitudes.
And don't forget the lip balm. Aloe Gator is a popular among people who enjoy winter sports, according to the REI website.
Go prepared and you'll have a better time, Boos said.
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