Convertible Photochromic: Our Photochromic Lenses are made from optical grade polycarbonate and are both impact and scratch resistant. They block 100% of harmful UV rays and are horizontally decentered to eliminate distortion caused by the frame wrap. Photochromic lenses darken when exposed to UV light. We do not start our photochromic lens at a clear tint for 2 reasons. Most sportsmen do not need a clear tint and because our lenses start at a usable tint they will get darker than the typical photochromic sports lens. Competition shooters, golfers and other sports enthusiasts love the fact the lenses automatically adjust to changing light conditions. We offer Yellow to Gray/Green, Rose to Brown, and Vermillion to Purple transition colors.