Customized Z-lens design program
View Patent ↗Embodiments of the invention pertain to a method for producing a spectacle lens with optimal correction across the entire lens taking into account the patient's complete measured wavefront. Specific embodiments can also take into account one or more additional factors such as vertex distance, SEG height, pantoscopic tilt, and use conditions. The lens wavefront can be achieved by optimizing a corrected wavefront, where the corrected wavefront is the combined effect of the patient's measured wavefront and the lens wavefront. The optimization of the corrected wavefront can involve representing the measured wavefront and the lens wavefront on a grid. In an embodiment, the grid can lie in a plane. During the optimization, a subset of the grid can be used for the representation of the measured wavefront at a point on the grid so as to take into account the portions of the measured wavefront that contribute to the corrected wavefront at that point on the grid.
1. A method for determining a lens wavefront, comprising:
measuring a patient's wavefront to create a pupil aberration p (n, m);
n
,
m
=
-
L
2
,
…
,
L
2
,
wherein the pupil aberration p (n, m) is represented on a grid, where n, m are indices of matrix elements, and L is the total number of pixels on a side of the grid,
generating a plurality of corrected wavefronts a ij (n, m); where i, j are indices of i th horizontal and j th vertical positions, wherein each corrected wavefront in the i th and j th position, a ij (n, m), is expressed as a ij (n, m) p (n, m)+s(n+i, m+j), where s(n+i, m+j) is a lens wavefront in the (n+j) th horizontal and (m+j) th vertical position, wherein the pupil aberration p(n, m) and the lens wavefront s(n+i, m+j) are represented on a grid and i represents the i th horizontal position and j represents the j th vertical position on the grid;
generating a function of the plurality of corrected wavefronts a ij ;
determining a lens wavefront by optimizing the function of the plurality of corrected wavefronts a ij ; and
producing a lens taking into account the lens wavefront.
2. The method according to claim 1 , wherein generating the function of the plurality of corrected wavefronts a ij comprises computing orthogonal components of a ij for a pupil centered at a specific point of the lens wavefront for each combination of the i th horizontal position on the grid and the j th vertical position on the grid.
3. The method according to claim 2 , wherein computing orthogonal components of a ij (n, m) comprises computing the inner product of a ij (n, m) with a set of orthogonal functions centered at a point of interest on the grid.
4. The method according to claim 2 , wherein computing orthogonal components of a ij (n, m) comprises convolving a ij (n,m) with a set of orthogonal functions centered at a point of interest on the grid.
5. The method according to claim 1 , wherein producing the lens further comprises fitting the lens wavefront across the lens.
6. The method according to claim 1 , wherein the grid is an 8×8 grid and a pupil is represented as a 3×3 subgrid within the 8×8 grid.
7. The method according to claim 3 , wherein the set of orthogonal functions are represented as approximations of Zernike polynomials.