| 摘要 |
PROBLEM TO BE SOLVED: To provide a progressive refractive power lens capable of realizing optimum design agreeing with the diopteric power of the lens even though a principal gazing line on a progressive surface is an umbilical line. SOLUTION: The progressive refractive power lens is equipped with a distant view part region arranged at the upper part of the lens, a near view part region arranged lower than the distant view part region and having larger refractive power than the distant view part region, and a progressive band which is arranged between the above-mentioned regions and where refractive power is progressively changed. The principal gazing line S1 on the progressive surface 15 formed on the surface of the lens is set to the umbilical line so as to restrain a surface astigmatism, and also the back surface of the lens is corrected so that the principal gazing line on the back surface side of the lens may not be the navel line, whereby the surface astigmatism is caused. Thus, the astigmatism of transmitted light transmitted through the principal gazing line on the back surface side is restrained. COPYRIGHT: (C)2005,JPO&NCIPI
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