If you don’t have a proper sunglass cloth on hand, one of the best ways to clean glasses quickly is to breath on them or get them wet with water (not saltwater before wiping them gently with a soft cloth. You should not use paper products (toilet paper, napkin, or paper towel as these are highly abrasive and scratch the lens coating. also, when saltwater dries on a lens, use soap and water and before wiping to avoid scratching the lens surface and coatings. For a more thorough cleaning, you should routinely wash your glasses. Start by cleaning the nose pads and then rinsing the glasses under warm water to remove dirt and surface residue. then, apply a small amount of mild detergent to your clean fingers and gently move the soap across the lenses in a circular motion. Finally, rinse the glasses again under warm water; if they are really clean, the lenses will repel water, so all that you need to do is dry the frames with a soft cotton cloth.