High quality 1.56 Blue Cut Photochromic Progressive Resin Optical Lens

"When a beam of light parallel to the main optical axis passes through a convex lens and intersects at a point, this point is called the focal point. The plane passing through the focal point and perpendicular to the optical axis is called the focal plane.". There are two focal points. The focal point in the object space is called the "object focal point", and the focal plane there is called the "object focal plane"; On the contrary, the focal point in the image space is called the "image focal point", and the focal plane there is called the "image focal plane.".

A thin lens is one in which the thickness of the central portion is large compared to the radius of curvature of both sides. In the early days, the camera was only equipped with a convex lens, so it was called a "single lens". With the increasing development of technology, modern lenses have a number of convex and concave lenses with different forms and functions that form a converging lens, known as a "compound lens.". The concave lens in a compound lens serves to correct various aberrations.