Patent ID: 7364292
Filing Date: 2008-04-29
Classification: G02C

Abstract:
1. A method of designing a progressive power lens group as a set of progressive power lenses, each having a first refractive section having a refractive power for seeing an object located at a predetermined distance, a second refractive section having a refractive power for seeing an object located at a near distance, and a progressive section with its refractive power progressively changing from the first refractive section to the second refractive section, the progressive power lens group satisfying: a condition where the first refractive sections differing in refractive power can be selected; a condition where at least two additions can be selected for the first refractive section having an identical refractive power; a condition where refractive indexes of materials of the progressive power lenses are identical; and a condition where design concepts of the progressive power lenses are standardized, the method comprising: designing the progressive power lenses so that for the progressive power lenses identical in addition, the smaller the refractive power of the first refractive section is, the shorter a distance in a vertical direction between a fitting point and a refractive power measurement point of the second refractive section is, and for the progressive power lenses identical in the refractive power of the first refractive section, the larger the addition is, the longer the direction in the vertical direction between the fitting point and the refractive power measurement point of the second refractive section is.