If your sunglasses was stained with water spot, you just need to turn the faucet on, get the water warm not hot, hold your glasses by the earpieces and run them under the warm water for about twenty seconds per lens. Do this for the front and back of both. After you clean your glasses, you’ll want to dry them before putting them on your face. There are several ways to do this. The gentlest way is to simply give them a couple little shakes over the sink, set them on a clean cotton towel, and allow them to air dry. If you’re the impatient type, set them on a towel and use a blow dryer set on the lowest temperature possible. If you have really hard water and don’t want to risk water spots on the lenses, use a soft cotton towel or a lens cleaning cloth, hold the glasses by the frames, and gently wipe them down.