| 摘要 |
<p>A method is described for making molds for the casting of resin ophthalmic lenses having segments of prismatic optical effect. A first mold surface is formed in a first blank. A second blank, having a recess therein shaped to the outline of the desired lens segment, is adhered to the first blank's mold surface. A second mold surface is then formed in the blank resulting from the connection of the first and second blanks. The first and second mold surfaces are each portions of surfaces of revolution having first and second axes of symmetry, respectively. The second surface has an effective center of curvature on the second axis. The second surface is so formed in the resulting blank that the first and second axes, if they intersect, do so at a location on the second axis other than at substantially the center of curvature of the second surface.</p> |
