I use it every day at the factory and it is not so expensive so I will exchange it as it gets scratched or becomes difficult to see. It is good because it is not cloudy with exhalation and sweat as much as you use. Wash the lens with your soap for hand washing and the inner coating gradually becomes white and muddy, so it is better to wash soap on the inside. Wiping the inside with alcohol will peel off the coating. Even if I wiped the front side, it was fine.