What are the purposes of lens tints and coatings?
Lenses of any material can be treated with coatings to give the lenses desired properties. Scratch-resistant coatings applied to the front and back of a lens can reduce the risk of sight-marring scratches for glass and plastic lenses. Ultraviolet-resistant coatings can be applied to all lenses; they are not needed for polycarbonate lenses, which have built-in ultraviolet resistance. Antireflective coatings, similar to those on microscope and camera lenses, reduce glare by blocking reflected light, a benefit that is especially important for night driving. Antireflective lenses also make lenses appear thinner, a cosmetic benefit. A wide variety of tints and coatings are available for modern lenses: Glass lenses are tinted by adding oxides to the glass during the manufacturing process. Plastic lenses can be tinted in a wide variety of shades and colors by dipping the lenses in special dyes. Tints increase comfort in bright light situations, reduce glare from computer screens or fluorescen
