Marker has developed the revolutionary NMT OPTICS coating for all lenses (except 4:3). It works similarly to the extra membrane or third eyelid that many animals have to provide extra protection to their eyes. NMT OPTICS (Nictitating Membrane Technology) have an extremely scratch-resistant surface that always supplies the best possible clarity. It prevents water, grease, or dust from sticking, and moisture wicks away immediately. Fingerprints, dust and sweat have no surface to cling to, and are easy to remove. Our NMT-coated lenses offer crystal-clear visibility for years.