Patent ID: 7874673
Filing Date: 2011-01-25
Classification: G02C

Abstract:
1. A progressive power lens, comprising: a pair of an outer refractive surface and an inner refractive surface, at least one of the outer refractive surface and the inner refractive surface being a progressive surface, relationships as follows being defined with respect to a lens to be actually worn: where: SPH represents a spherical power; CYL represents a cylindrical power; AX represents a cylinder axis; ADD represents an addition power; N represents a refractive index of the lens; SV represents a vertical refractive power; Cm relationships as follows being defined with respect to a lens designed for a standard pantoscopic angle: where: Cm relationships as follows being defined: where: ΔPA represents a deviation of the pantoscopic angle between the pantoscopic angle of the lens to be actually worn and the standard pantoscopic angle; and ΔDm(Y) represents a difference between a sum of the surface powers of the cross-sections of the outer surface and the inner surface of the lens to be actually worn taken along the main fixation line and a sum of the surface powers of the cross-sections of the outer surface and the inner surface of the standard lens taken along the main fixation line, and relationships as follows being satisfied: