Been wearing eyeglasses for years so I've tried everything. The best method I've found (partly because of it's side effect-a clean shield) is to wash your face plate, inside and out, with liquid dish soap or if you're in a gas station or restaurant, with liquid hand soap. What you are doing is washing the impurities off. It is this crap that the moisture sticks to. You will find that it may fog briefly on exhalation but quickly clear up. Easy, free.