VISION CORRECTION LENS DESIGNING METHOD AND VISION CORRECTION LENS

摘要

PROBLEM TO BE SOLVED: To provide a vision correction lens that can improve contrast sensitivity in the dark place at night time, etc.SOLUTION: A vision correction lens is characterized in that a depth of focus extension component represented by Ar(where r is a distance from the z axis, and A is a constant) is added to a z coordinate value of a refraction surface determined based on prescription power for extending a depth of focus, when assuming that an anteroposterior axis passing the geometric center of the lens is the z axis and the direction moving to the rear of the lens is the positive direction of the z axis. The depth of focus becoming short (shallow) in the dark place is extended and a focal point is easy to come to match even an object in the front or rear of the original focal point, and therefore the contrast sensitivity in the dark place can be improved.SELECTED DRAWING: Figure 1