TIPS: 1. Do not scratch the lens with sharp objects; 2. Do not clean the lens with any fabric or tissue but cleaning cloth; 3. Do not put the glasses into pocket directly,but with a case first; 4. After wearing glasses for a while,If you find that the glasses are loose, usually because the screws on the glasses are loose, you can use the screwdriver we sent you to tighten the screws on the glasses