What is the function of aspherical mirror in digital camera lens?

Using aspherical lens in lens design can reduce the number of lenses, reduce the weight and volume, and provide better optical performance.

The function of aspheric lens is to change the curvature of lens surface, so that the focal positions formed by paraxial light and far-axis light coincide. When the near-axis light and the far-axis light both fall on the same focal plane, the light spot will disappear and the imaging clarity will be improved. It is generally used to solve the problems of glare and edge deformation in wide-angle and zoom lenses, and can also improve the optical quality in telephoto lenses.