1-Never clean your sunglasses with paper towels or clothing, which can leave scratches.Just use clean water and included cloth to clean it. 2-Never leave your sunglasses under car’s front window, especially in summer. Prolonged exposure to the oven-like temperatures inside a car can degrade the lens.
https://www.amazon.com/Goggles-Prescription-Glasses-Sunglasses-Protection/dp/B07BWNBHG4

