Wavefront-generated custom ophthalmic surfaces
AssigneeBausch & Lomb Incorporated
InventorGriffith E. Altmann
Life of this patent
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Abstract
An embodiment of the invention is directed to a method for determining an anterior or posterior surface parameter of an ophthalmic correcting surface (e.g., custom contact lens “CCL,” customized IOL, custom inlay, customized corneal surface) from a wavefront aberration measurement of an eye. A preferred embodiment relates to determining an anterior surface parameter of a dry, CCL designed to operate at 555 nm. An algorithm sets forth the method comprising misalignment correction, chromatic aberration correction, and power shift correction due to differences between aberration measurement wavelength and peak vision wavelength, and differences between aberration measurement location and aberration correction location. A device readable medium is the preferable vehicle for the algorithm.
Claims30
A method for determining a surface parameter of an ophthalmic correcting surface from a wavefront aberration measurement of an eye, comprising:
- a) obtaining a wavefront aberration measurement of a patient's eye at a known measurement plane location using a known measurement wavelength;
- b) correcting the wavefront aberration measurement as necessary to compensate for a measurement device-induced misalignment of the measurement;
- c) determining a defocus refractive correction based upon the aberration measurement;
- d) determining a chromatic aberration correction for the defocus correction;
- and
- e) determining a power shift correction to account for a correction surface location different from the measurement plane location.
A method for determining a surface parameter of an anterior surface of a dry, custom-correction contact lens, designed to operate at 555 nm, from a wavefront aberration measurement of an eye, comprising:
- fitting a trial lens on a patient's eye;
- making a wavefront measurement through a central optical zone region of the trial lens, and at a selected measurement plane location using a known measurement wavelength;
- determining an amount and direction of rotation of the trial lens on the patient's eye;
- correcting the wavefront aberration measurement as necessary to compensate for a measurement device-induced misalignment of the measurement;
- determining a defocus refractive correction based upon the aberration measurement;
- determining a chromatic aberration correction for the defocus correction;
- determining a power shift correction to account for a correction surface location different from the measurement plane location;
- converting the aberration measurement from a wavefront deformation to a wet lens surface deformation;
- and
- modifying a wet lens deformation parameter to obtain a corresponding dry lens deformation parameter.
Dependencies are inferred from the claim text.