| 摘要 |
<p>A method and system provide an ophthalmic device. The ophthalmic device includes an ophthalmic lens having an anterior surface, a posterior surface, an optic axis and at least one diffractive grating pattern. The diffractive grating pattern(s) are disposed on at least one of the anterior surface and the posterior surface. The diffractive grating pattern(s) includes zones corresponding to distance ranges from the optic axis. Each of the zones has a plurality of echelettes having a radius of curvature corresponding to a focal length. The radius of curvature for each of at least a portion of the zones is different from the radius of curvature for another of the zones.</p> |
