| 摘要 |
Presbyopia correction contact lens including an optical zone consisting of a substantially circular central optical portion and an annular peripheral optical portion outside the central optical portion, the central and peripheral optical portions having respective different optical power values, so-that the central and peripheral optical portions provide one and the other of a near vision correction region and a distant vision correction region, respectively, wherein the central and peripheral optical portions provide the near and distant vision correction regions, respectively, and the optical zone includes a front surface having an arcuate configuration with a substantially constant curvature in cross section taken in a plane parallel to a diametric direction of the contact lens, and a back surf ace consisting of a central portion corresponding to the central optical portion and a peripheral portion corresponding to the peripheral optical portion, the central portion of the back surface having an arcuate configuration with a substantially constant curvature in cross section taken in said plane, which curvature is different from that of the peripheral portion of the back surface.
|
