This 55mm diameter by 3.5mm thick meniscus glass is made of schott glass. We have hundreds of these in storage for some time now and we need to get them out. We believe that this item is a blank to make eyeglasses. Polished on both sides so it acts as a window. The positive curve side is 4.25 diopters and the negative curve side is -8.25 diopters. Start your own eyeglass company today.
