Sunglasses are not just a fashion accessory. Exotic lens colors may be stylish, but gray because it absorbs all colors about equally diminishes color perception the least. Green is second-best. Sunglasses should block 99-100% of both kinds of ultraviolet (UV) radiation: UVA and UVB. Look for this information on a label or hangtag. If glare is a problem, polarized lenses are a good choice. "Mirror" lenses, the type favored by skiers, also help to decrease glare, because they screen out more light than do tinted lenses.