Progressive multifocal lens, progressive multifocal lens design method, progressive multifocal lens processing method

摘要

PROBLEM TO BE SOLVED: To inexpensively provide a progressive multifocal lens which is easy on the eyes.SOLUTION: In a set of right and left progressive multifocal lenses (1L and 1R), one is a non-adjustment side lens in which length of a progressive zone 10 is L, add at a lower end 12 of the progressive zone is , distance going from an upper end 11 of the progressive zone to the lower end is considered as x, and a prism degree at arbitrary distance x=xis considered as P, and the other is an adjustment side lens in which the length of the progressive zone is L, the add at the lower end of the progressive zone is , and the prism degree at the arbitrary distance x=xis considered as P, the progressive zone of the adjustment side lens satisfies , and LL, add at a position of x=Lis . In the non-adjustment side lens and the adjustment side lens, difference in the prism degrees |P-P| in x=xis L=L, and equal to or less than difference in the prism degrees in x=xwhen it is assumed that L=L, and =in the case of xL.