A drop of Dawn soap on each lens. Wash under hot water faucet in kitchen sink. Rub with your finger and thumb until the glass gets squeaky clean. When glass is this clean you can blot it dry with a paper towel. Everyone says paper towels are a no no. If the glass is clean. Paper towels won't scratch them. Rubbing them with a clean microfiber cloth designed for cleaning glasses will scratch when they have dust and grime on them.