PhotoCarbon lenses are polycarbonate photochromic lenses. Polycarbon lenses offer great clarity with superior shatter resistance. This means less distortion, more fish spotted and extremely durable lenses. Polycarbonate lenses are also lighter than normal plastic or glass lenses. Photochromic lenses are the best all-round option and work in almost every condition from low light overgrown rivers to bright sunshine. Photochromic lenses darken on exposure to UV radiation. PhotoCarbon series lenses start very light and darken very linearly when UV light is increased. These lenses have a discreet Flashlight gold mirror finish.  NOTE: Photochromic lenses are not a good option for driving a car as the UV light does not penetrate the car windshield thus not darkening enough for bright sunlight.