Aspherical lenses: Its surface curvature is different from ordinary spherical lenses. In order to pursue the thinness of the lens, it is necessary to change the curved surface of the lens. In the past, the use of spherical lens design will increase the aberration and deformation, resulting in Obvious undesirable phenomena such as blurred images, distorted vision, and narrow field of view. The current aspheric design corrects the image and solves problems such as distortion of the field of view. At the same time, it makes the lens lighter, thinner, and flatter.