METHOD FOR DESIGNING VISION CORRECTION LENS, AND VISION CORRECTION LENS

摘要

A corrective lens that can improve contrast sensitivity in a dark place, for example, at night is provided. When an axis in the anteroposterior direction passing through the geometric center of a lens is defined as the z-axis and a direction extending to the rear side of the lens is defined as the positive direction of the z-axis, a focal depth extension component represented by Ar 3 (where r is the distance from the z-axis and A is a constant) is added to the z-coordinate value of a refractive surface determined based on a prescription power to increase the focal depth. The focal depth that decreases (shallows) in a dark place is increased to facilitate focusing on a target object located in front of or behind the original focal point. This can improve contrast sensitivity in a dark place.