PROGRESSIVE ADDITION LENS

摘要

There is provided a progressive addition lens capable of improving both of astigmatism and power error on a peripheral part of a distance area, including a distance area used for a distance vision, and other area different from the distance area, wherein at least one of an eyeball side surface of a wearer and an object side surface in the progressive addition lens is formed into an aspheric form, and when a prescription value T to be obtained from formula “S+C/2” expressed by a prescribed spherical power S and a cylindrical power C, is minus, the area where a power deviation ΔD of a spherical equivalent power D from the prescription value T goes negative, exists on principal sight line in the distance area.

主权项

1. A progressive addition lens, comprising a distance area used for a distance vision, and other area different from the distance area, wherein at least one of an eyeball side surface of a wearer and an object side surface in the progressive addition lens is formed into an aspheric form, and when a prescription value T to be obtained from formula “S+C/2” expressed by a prescribed spherical power S and a cylindrical power C, is minus, the area where power deviation ΔD from the prescription value T of spherical equivalent power D goes negative, exists on principal sight line in the distance area.