Ophthalmic lenses capable of reducing chromatic aberration

A method of designing an aspheric ophthalmic lens with both refractive and diffractive powers that is capable of reducing chromatic aberration and at least one monochromatic aberration of an eye characterized by combining aspherical refractive and diffractive surfaces, selecting an appropriate eye model, establishing a design lens having at least one aspheric surface with a capacity to reduce monochromatic aberration in said eye model, establishing a diffractive lens element that corrects for chromatic aberration of the model eye;

• adjusting the lens surface design in order to obtain a suitably high polychromatic image quality in a form that is weighted to comply with a spectral merit function, wherein said spectral merit function describes a wavelength dependent sensitivity of an eye for selected lighting conditions, wherein the spectral merit function is obtained from a combination of functions, and wherein the function is selected from the group consisting of photopic, scotopic, and mesotopic luminosity functions;
• determining the efficiency for the higher order foci generated from the diffractive lens element, and introducing in said design lens a spectral filter that eliminates wavelengths or reduces transmission of wavelengths in a manner that said higher foci have reduced efficiency within the range of visible light.

A method of designing an aspheric ophthalmic lens with both refractive and diffractive powers that is capable of reducing chromatic aberration and at least one monochromatic aberration of an eve characterized by combining aspherical refractive and diffractive surfaces, selecting an appropriate eye model, establishing a design lens having at least one aspheric surface with a capacity to reduce monochromatic aberration in said eye model, establishing a diffractive lens element that corrects for chromatic aberration of the model eye;

• and adjusting the lens surface design in order to obtain a suitably high polychromatic image quality in a form that is weighted to comply with a spectral merit function, wherein said spectral merit function describes a wavelength dependent sensitivity of an eye for selected lighting conditions, wherein the diffractive lens element is a diffractive surface profile consisting of a number of concentric rings, and wherein the profile height of the diffractive surface profile, when multiplied with a difference in refractive index between the design lens and a surrounding medium equals an integer number of the design wavelength.