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.