Patent ID: 7422325
Filing Date: 2008-09-09
Classification: G02C,H04L

Abstract:
1. A method of designing a spectacle lens having a combined refracting surface in at least one of two refracting surfaces at object and eye sides structuring the spectacle lens, the combined refracting surface having an astigmatism correcting toric surface combined with a progressive refracting surface having a distance-use area, a near-use area different in refractive power from the distance-use area and a progressive area having a refractive power progressively changing between those, the method comprising: establishing reference lines extending in at least three of radial directions from a center point in a vicinity of a geometric center of the spectacle lens to any one of both ends of the distant-use area, the near-use area, and a center region; establishing reference lines extending in at least one of radial directions from the center point of the spectacle lens to the other of the distant-use area and the near-use area; determining an aspheric addition amount for a refractive power that is along each of the reference lines; and determining an aspheric addition amount, by interpolation, for a refractive power of between the reference lines, wherein provided that a coordinate system is defined, as viewing the combined refracting surface from front of spectacles being worn, with X-axis in a left-right direction, Y-axis in a vertical direction being a distance direction, Z-axis in a depth direction and the center point as to represent a coordinate forming a basis of the combined refracting surface as z