Glass lenses, as the name suggests, are lenses made of glass. The lens is also called the center of the mirror, which is the center of the painting after mounting. It is suitable for clipping in the frame, so it is called the center of the mirror. Its form can be horizontal or vertical, which is a simple and convenient installation. Classification: Lenses can be divided into the following four types according to different materials: resin lenses, special lenses, space lenses, glass lenses, glass lenses, glass lenses, which are more scratch-resistant than lenses of other materials, but are relatively heavy in weight. Its refractive index is relatively high: ordinary sheet is 1.523, ultra-thin sheet is: 1.72 or more, and can be as high as 2.0. The main raw material of glass lenses is optical glass.