| 摘要 |
PROBLEM TO BE SOLVED: To provide a designing method to obtain favorable optical performance of the prescribed face of a lens with respect to various specifications associated with individual information such as the prescription for the eyeglass wearer. SOLUTION: In figure, 1 represents the rotatory point of an eyeball, 2 represents a first eye position, 3 represents a second eye position and 4 represents a third eye position, with bold lines drawn at each eye position representing the horizontal meridian and the vertical meridian (main longitude) of the cornea. In particular, the directions of the horizontal meridian and the vertical meridian of the cornea in the third eye position 4 are not matched with the directions of the horizontal meridian and the vertical meridian in the first eye position. In order to correct the aberration of the eyeglass lens not only in the first and second eye positions but in the third position under the conditions in conformity with the prescription and the use environment of the wearer, the prescribed face of the lens is made aspheric with the astigmatic axis of the eye in any eye position taken into consideration according to the Donders-Listing's law. COPYRIGHT: (C)2004,JPO
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