Lens is a transparent material with one or more curved surfaces made of optical materials such as glass or resin. After polishing, it is often assembled into glasses with a glass frame to correct the user’s vision and obtain a clear field of vision.
The thickness of the lens mainly depends on the refractive index and degree of the lens. Myopic lenses are thin in the center and thick around the edges, while hyperopic lenses are the opposite. Usually the higher the degree, the thicker the lens; The higher the refractive index, the thinner the lens