Spectacle lenses can be coated with ant-reflective coatings in order to cut down on glare. They also sometimes have scratch coatings to help resist scratches. Because the coatings are applied to the surface of the lens and are not part of the lens, the coating eventually might peel off. If this happens to your glasses, there are steps you can take to remove the coatings from your lenses. This method only works on plastic lenses. Do not use hydrofluoric acid on glass lenses.
Use a cotton swab to apply a thick coating of Armour Etch to both sides of the lens.
Let the glasses sit with the coating on them for at least five minutes.
Do not rub the compound into the lens, just apply the coating and let it sit.
Rinse the lens with warm, soapy water. Rinse again with clear water and wipe dry with a soft, clean towel.
Repeat the process if necessary.
Test a small, inconspicuous spot on your lens first to make sure the acid will properly remove the coating. The upper, outside corner of a lens works well.
Be careful when using hydrofluoric acid. Read the product's warning label and follow the safety instructions. Wear protective clothing, safety glasses or safety goggles. Wear heavy-duty rubber gloves that do not leak. Use the product in a well-ventilated area. Keep children and pets away from areas where these products are stored or used. Do not use hydrofluoric acid on glass lenses, only on plastic. Products such as Armour Etch will frost glass lenses and you will not be able to see through them.