All Method Seven lenses are best cleaned by blowing all loose dust, dirt and particulates from the lens, and then using warm water and a drop of dish soap. DO NOT use Windex, alcohol or ammonia based glass cleaners! Commercially available glass cleaners made for coated optics or sunglasses are safe to use. We do not recommend using paper towels, paper tissues, or your t-shirt as these may scratch the lens. A mirco-fiber cleaning cloth / pouch was provided with your glasses. This material or something similar is the best materials for cleaning the surface of your lenses. Lastly, don't forget to check and tighten screws regularly.