| 摘要 |
An eyeglass lens of the present invention has a surface which is a refracting surface arranged such that two coordinate axes X and Y are set to contact with the refracting surface at a determined point thereon while directions of the coordinate axes and an XY plane including the two axes are determined, that a perpendicular line is dropped toward the XY plane from an arbitrary point on the refracting surface, and then X, Y coordinates of an intersecting point between the perpendicular line and the XY plane are denoted by x and y, respectively, and the length of the perpendicular line by z, and that a value of z is expressed as follows: <IMAGE> (1) <IMAGE> where r2=x2+y2; Cx, Cy, Kx, Ky, An,m,j are constants to define the shape of lens; n, m, j are integers satisfying conditions of 2</=n, 0</=m, 0</=j, and l</=m+j; coefficients satisfy the following conditions: |An,m,j| </= 2.0 x 10-n, (2) <IMAGE> (3) <IMAGE> (4) which cannot be simultaneously zero.
|
