Glare is reflected light that travels on a horizontal plane. Virtually any surface can be a source of glare, including water, sand, pavement, ice and snow. The lenses in the Native Bolder Polarized Sunglasses incorporate a polarized filter, which absorbs the horizontal light, thus eliminating the glare. A set of Sport-Flex lenses, for low light conditions, is included.Fits large faces. Double Snap-Back? interchangeable lens system. Polarized lenses eliminate glare. Crystal carbonate lenses are impact resistant and block 100% harmful UV (ABC). Rhyno-Tuff? air frames weigh less than 1 oz. Venting above lenses to prevent fogging. Cushinol? nose pads for a comfortable secure fit. Cam action hinges. Mastoid temple grip. Anti-ocular intrusion system to impact protection. Includes sport-flex (low light) lenses. Hard case included.