photochromic lenses darken when exposed to sunlight, mainly ultra-violet (UV) light. They provide wearers with the best possible vision in all lighting through different shades of tint. Photochromatic lenses usually darken within seconds and will maintain their effect while you're in the light. Photochromic lenses contain the photochromic molecules silver halide or silver chloride. Under UV light, these molecules react in a chemical process that causes them to change shape and darken. Photochromatic lenses are great in any kind of environment as they eliminate glare, increase visual clarity, enhance contrast and reduce eye strain. Photochromic lenses offer 100% UV protection.
