To take good care of your eyeglasses at the beach, you shall keep your eyeglasses away from sands and avoid long time expose to sun. So, you shall always take a glasses case so as to keep eyeglasses while you don't need it. Please do not put your eyeglasses on the beach casually or put it in your hand bag without case, or put the glasses on your head. that actions will hurt your eyeglasses lenses. So, you shall put them in special eyeglasses cases, and then put it in your handbag or put it in some cool places.