| 摘要 |
PCT No. PCT/JP92/01730 Sec. 371 Date Sep. 2, 1993 Sec. 102(e) Date Sep. 2, 1993 PCT Filed Dec. 3, 1993 PCT Pub. No. WO93/14434 PCT Pub. Date Jul. 22, 1993In a contact lens (1) provided with a front curve (2) formed with a plurality of distance portion curved surfaces (F1, F2, . . . ) for seeing a distant place . . . )and a plurality of near portion curved surfaces (N1, N2, for seeing a near place arranged alternately and repeatedly in concentric zone shape, the distance portion curved surfaces formed at least a central zone of the front curve have respective curvature centers (OF1, OF2, . . . ) positioned increasing distance away from an optical axis and the front curve of the contact lens respectively, as the distance portion curved surfaces are located increasing distance away from the optical axis, and further the curvature centers of the distance portion curved surfaces are so arranged that light rays parallel do the optical axis and allowed to be incident upon the distance portion curved surfaces are focused at roughly the same point on the optical axis; and the near portion curved surfaces formed at least the central zone of the front curve have respective curvature centers (ON1, ON2, . . . ) positioned increasing distance away from the optical axis and decreasing distance close to the front curve of the contact lens respectively, as the near portion curved surfaces are located increasing distance away from the optical axis, and further the curvature centers of the near portion curved surfaces are so arranged that light rays parallel to the optical axis and allowed to be incident upon the near portion curved surfaces are focused at roughly the same point on the optical axis. Therefore, it is possible to realize a contact lens provided with a front curve formed with a plurality of distance portion curved surfaces and a plurality of near portion curved surfaces arranged alternately and repeatedly in concentric zone shape, from which spherical aberration can be removed.
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