Diffractive lenses for vision correction

Abstract

Diffractive lenses for vision correction are provided on a lens body having a first diffractive structure for splitting light into two or more diffractive orders to different focal distances or ranges, and a second diffractive structure, referred to as a multiorder diffractive (MOD) structure, for diffracting light at different wavelengths into a plurality of different diffractive orders to a common focal distance or range. In a bifocal application, the first and second diffractive structures in combination define the base power for distance vision correction and add power for near vision correction of the lens. The first and second diffractive structures may be combined on the same surface or located on different surfaces of the lens. The first diffractive structure may have blazed (i.e., sawtooth), sinusoidal, sinusoidal harmonic, square wave, or other shape profile. A sinusoidal harmonic diffractive structure is particularly useful in applications where smooth rather than sharp edges are desirable.