Sunscreens can protect our skin, but UV exposure can damage our eyes and the delicate skin surrounding them, causing burns, cataracts (clouding of the lens) and macular degeneration as well as cancerous and non-cancerous growths in and around the eyes. Wear sunglasses every time you're outside, no matter what the season and no matter what the cloud cover. During the summertime, UV radiation is three times higher than during the winter months, but summertime isn't the only time for eye protection. If you're at a high elevation, the level of ultraviolet radiation you're exposed to increases -- by as much as eight to 10 percent for every 1,000 feet above sea level. And don't forget that water, snow, and even sand and concrete reflect sunlight, increasing their harmful effects by as much as 80 percent [source: Skin Cancer Foundation].
Not all lenses protect against sun damage, though, so be sure to look for lenses that block 99 to 100 percent of both UVB and UVA rays -- especially important if you're partial to polarized, blue-blocking, mirror-coated or other specialty lenses, because not of them all offer UV protection.