Birdz Anti-fog is guaranteed to work. With that being said please remember one thing. There are hundreds of different types of glass, plastic, polycarbonate and Lexan lenses out there. That is not including the different types of coatings: Anti-reflective, transition, polarized. What we have done is found the best possible product to cover such a wide variety of lenses. Birdz products work on every type of lenses out there, but will work better on some lenses than others. Please make sure you are using the product correctly, and if you are not satisfied please contact us so we might be able to give you some tips on how to get the most out of Birdz Anti-fog. Birdz is an anti fog for visors. We manufacture Birdz anti fog for lenses and also is an anti fog for magnifications. All our products are manufactured in the United States and sold worldwide. Ten Birdz anti fog spray bottles - EASY TO CARRY - Compact anti fog solution. It is very light and fits in small pockets SAFE ON ALL LENSES - Birdz is the perfect lens, goggles and mask anti fog solution. It is safe for all lenses including eyeglasses, sunglasses, paintball masks, snorkel masks, swim goggles, camera lenses, dive masks, gun scopes, binoculars, safety goggles, ski masks and snowboard masks. LONGEST LASTING ANTIFOG FOR LENSES - Birdz anti fog for lens spray is for larger application and expensive optics. Equipped with a fine mist sprayer is perfect for any type of lens. EASY TO APPLY - spray a small amount with your finger, rub it in the lens until it completely dries (similar to wax on paint), and wipe off with a microfiber or cotton cloth. For this product to work most effectively, it must be reapplied every three to five days or every time you clean your lens. GUARANTEED TO WORK - Birdz Anti-fog is the best len