NOVELTY - An ophthalmic lens (10) comprises an optical filter operable to filter out a visible light having wavelength less than 450 nm; first diffractive structure (18) adapted to produce focus for visible light in first wavelength above 550 nm and to reduce longitudinal chromatic aberration to less than one diopter for incoming visible light in first wavelength range; a second diffractive structure (20) outside first diffractive structure in a radial direction and adapted to produce a focus for visible light in a second wavelength of 450-550 nm.
USE - As an ophthalmic lens (claimed), particularly intraocular lenses.
ADVANTAGE - The monofocal intraocular lenses (IOL) is made thinner than a similar monofocal IOL that is purely refractive on account of the improved visual acuity from chromatic aberration correction. The purely refractive IOL has better refractive performance, such as better correction for off-axis and peripheral rays, which ordinarily requires more refractive material. The chromatic aberration correction can improve visual acuity without requiring extensive modifications to the refractive properties of the IOL, which in turn requires less refractive material; and reduces a thickness of the IOL in order to permit a smaller incision.
DETAILED DESCRIPTION - An ophthalmic lens (10) comprises an optical filter operable to filter out at least visible light having a wavelength less than 450 nm; a first diffractive structure (18) adapted to produce a focus for visible light in a first wavelength above 550 nm and to reduce longitudinal chromatic aberration to less than one diopter for incoming visible light in the first wavelength range; a second diffractive structure (20) outside the first diffractive structure in a radial direction and adapted to produce a focus for visible light in a second wavelength of 450-550 nm and to reduce longitudinal chromatic aberration for incoming visible light in the second wavelength range to less than one diopter while allowing longitudinal chromatic aberration in the first wavelength range in an amount greater than the first diffractive structure. The optical filter comprises a UV-absorbing material. An INDEPENDENT CLAIM is included for manufacturing an ophthalmic lens, involving determining a first profile for a first diffractive structure adapted to produce a focus for visible light in a first wavelength range above 550 nm; determining a second profile for a second diffractive structure outside the first diffractive structure in a radial direction and adapted to produce a focus for visible light in a second wavelength of 450-550 nm; forming an ophthalmic lens with the first profile and the second profile and incorporating an optical filter operable to filter out at least visible light having a wavelength less than 450 nm.
DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of intraocular lenses.
Ophthalmic lens (10)
Optic (12)
Anterior surface (14)
Posterior surface (16)
First diffractive structure (18)
Second diffractive structure (20)
