| 摘要 |
PURPOSE:To apply lenses to both a far-sighted and a near-sighted presbyopic patient by designing the lenses while importance is attached to a far-sight visual field when the mean diopters of far sight are >=+1.00 or to a near-sight visual field when <=-1.00. CONSTITUTION:The hatched parts of a right-eye lens 1 used for the far-sighted presbyopic person and a right-eye lens 2 used for the near-sighted presbyopic person are areas where astigmatism exceeds a 0.50 diopter, and marks '+' and '.' indicate a far-sight eye point position and a near-sight diopter measurement position. Then three areas (Ap, Bp, and Cp in figure 1 and Am, Bm, and Cm in figure 2) are sectioned by two horizontal lines passing respective points. In such a case, Ap<Am and Cp<Cm; and a wider far-sight visual field is obtained for the far-sighted presbyopic person and a wider (horizontally) near-sight visual field is obtained for the near-sighted presbyopic person.
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