Multifocal lens having reduced chromatic aberrations
AssigneeAlcon Inc.
InventorsMyoung-Taek Choi, Xin Hong, Yueai Liu
Life of this patent
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Abstract
A method and system provide a multifocal ophthalmic device. The ophthalmic lens has an anterior surface, a posterior surface and at least one diffractive structure including a plurality of echelettes. The echelettes have at least one step height of at least one wavelength and not more than two wavelengths in optical path length. The diffractive structure(s) reside on at least one of the anterior surface and the posterior surface. The diffractive structure(s) provide a plurality of focal lengths for the ophthalmic lens.
Claims15
A multifocal ophthalmic lens comprising:
- an anterior surface;
- a posterior surface;
- and
- a single diffractive structure comprising a plurality of echelettes having a single physical height, the plurality of echelettes having a step height of at least one wavelength and not more than two wavelengths in optical path length, the diffractive structure residing on at least one of the anterior surface and the posterior surface, the diffractive structure providing:
- a first diffractive order for a first focus corresponding to a first focal length;
- and
- a second diffractive order for a second focus corresponding to a second focal length, the second focal length being different from the first focal length;
- wherein the diffractive structure excludes a 0th diffractive order.
A multifocal ophthalmic device comprising:
- an ophthalmic lens having an anterior surface, a posterior surface, and a plurality of echelettes having a single physical height and included in a single diffractive structure, the plurality of echelettes having a step height of at least one wavelength and not more than two wavelengths in optical path length, the diffractive structure residing on at least one of the anterior surface and the posterior surface, the diffractive structure providing:
- a first diffractive order for a first focus corresponding to a first focal length, and
- a second diffractive order for a second focus corresponding to a second focal length, the second focal length being different from the first focal length;
- wherein the diffractive structure excludes a 0th diffractive order;
- and
- a plurality of haptics coupled with the ophthalmic lens.
A method for fabricating a multifocal ophthalmic lens comprising:
- designing an ophthalmic lens configured for use based upon a wavelength, the ophthalmic lens having an anterior surface, a posterior surface, and a plurality of echelettes having a single physical height and included in a single diffractive structure, the plurality of echelettes having at least one initial step height, the diffractive structure residing on at least one of the anterior surface and the posterior surface, the diffractive structure providing:
- a first diffractive order for a first focus corresponding to a first focal length;
- and
- a second diffractive order for a second focus corresponding to a second focal length, the second focal length being different from the first focal length;
- wherein the diffractive structure excludes a 0th diffractive order;
- adding one wavelength to the at least one initial step height to provide at least one final step height;
- and
- fabricating the ophthalmic lens using the at least one final step height for the diffractive structure.
Dependencies are inferred from the claim text.