Anti-reflective coatings (A-R coating) are metallic oxide coating that are vacuum-applied to the lens surface to reduce reflections from lens surface and eliminate reflections from the back. This reduced amount of reflection enhances the appearance of the glasses and also allows more light to pass through the lenses, which can improve vision in low-light situations. Anti-reflective coating also provide some protection from scratching.
Tinted Lens is another option in colored lenses is a tint, which remains constant at all times. Tints are available on polycarbonate lenses and can be had in almost any color of the rainbow.
Photochromic Lenses change from light to dark depending on the amount of ultraviolet light they are exposed to. These lenses do not becomes as dark when driving because the car’s windshield absorbs some of the ultraviolet light that causes the lenses to darken. Early photochromics were strictly glass lenses, but today, you can choose from regular plastic, polycarbonate and high-indexglass and plastic.