| 摘要 |
This invention relates to a lens for presbyopia free from distortional aberration for use in correcting an old-age eyesight. In the lens for presbyopia with a front lens surface having a smaller radius of curvature than a rear lens face, a lens surface has a refractive power successively corrected as the lens surface extends radially outwardly away from a geometric center of the lens so that lateral magnifications for all principal rays always equal a lateral magnification for a paraxial range. This construction is entirely free from distortional aberration, and secures a greatly enlarged range of distinct vision.
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