Generalized presbyopic correction methodology
View Patent ↗An adaptive optics phoropter is aligned with a Badal optometer and an adjustable aperture component to subjectively determine an optimal vision correction as a power profile for an ophthalmic lens or ablating a cornea. The optimal power profile is preferably determined in an iterative process by adjusting the vergence of the Badal optometer and aperture size of the adjustable aperture component for power profiles with presbyopic power zones having different amplitudes, shapes, widths, and/or de-centering. Also included is a method of recursively computing a refractive surface with a regular presbyopic power zone (e.g., according to the optimal power profile) and adding it onto an underlying irregular Zernike-basis-set aberration-corrected surface in a linear fashion for fabricating an ophthalmic lens.
1. A method of determining a resultant refractive surface, comprising:
(a) determining a non-axi-symmetrical base refractive surface with correction for aberrations;
(b) defining a plurality of radial and azimuthal meridians on the base surface; and
(c) along each meridian, superimposing an axi-symmetrical power zone onto the non-axi-symmetrical base refractive surface to generate a resultant surface.
2. The method of claim 1 , wherein step (a) includes determining the non-axi-symmetrical base refractive surface by using an ophthalmic wavefront sensor.
3. The method of claim 1 , wherein step (b) includes defining 16 radial meridians and 5 azimuthal meridians on the base surface where the power zone is to be added.
4. The method of claim 1 , wherein step (c) includes applying a recursive function to build up the power zone along each meridian in a linear fashion.
5. The method of claim 4 , wherein step (c) further includes using a NURBS model for surface construction by boundary curves for recursively adding the power zone onto each meridian on the base surface.
6. A computer-readable medium encoded with computer-executable instructions for carrying out the method of claim 1 .
7. The method of claim 1 , further comprising (d) fabricating an ophthalmic lens with the resultant surface.
8. The method of claim 7 , wherein step (d) includes fabricating the ophthalmic lens of lathable silicon hydrogel.
9. The method of claim 7 , wherein step (d) includes fabricating the ophthalmic lens using a single-point diamond cutting system.
10. An ophthalmic lens fabricated by using the method of claim 7 .