Optic Nerve's PhotoMatic lenses represent a true technological advance in active sports lenses. Made of high-grade polycarbonate resin, they offer maximum impact and 100% UV protection. And, their Focalpoint technology optimizes the visual clarity. PhotoMatic lenses are engineered with advanced crystals cast into the lens during production that react and darken when exposed to UV light. The stronger the UV rays, the darker the lenses get, and in only 10 seconds from one extreme to the other. The lens starts as light brown, offering enhanced contrast and definition in low to variable light conditions, and changes to a dark brown for bright sun conditions (photo).