Apodized aspheric diffractive lenses

Abstract From the Canadian patent

Aspheric diffractive lenses are disclosed for ophthalmic applications. For example, multifocal intraocular lens (IOLs) are disclosed that include an optic having , an anterior surface and a posterior surface at least one of which surfaces , includes an aspherical base profile on a portion of which a plurality of diffractive zones are , disposed so as to generate a far focus and a near focus. The aspherical base profile , enhances image contrast at the far focus of the lens relative to that obtained by a , substantially identical IOL in which the respective base profile is spherical.