Limited echelette lens, systems and methods
Methods for designing an ophthalmic lens that provides enhanced image quality across a wide and extended range of foci include utilizing pupil size measurements and based on the measurements determining the size of echelettes.
1. A method of designing an ophthalmic lens comprised of utilizing pupil size measurements and based on the measurements determining the size of an inner echelette and between 1 and 4 peripheral echelettes to impose on the surface of a lens, wherein at least 2 echelettes are not adjacent to each other and are separated by a refractive region.
2. The method according to claim 1 , in which the measurements are based on the pupil sizes of a group of patients.
3. The method according to claim 1 , wherein the inner and peripheral echelettes are characterized by a surface area between 1 and 7 square millimeters.
4. The method according to claim 1 , wherein the inner and peripheral echelettes have the same surface area.
5. The method according to claim 1 , wherein the inner echelette and the peripheral echelette(s) are not separated by a refractive region.
6. The method according to claim 5 , wherein the inner echelette has a diameter within a range from about 1 mm to about 5 mm.
7. The method according to claim 1 , wherein the lens further comprises a peripheral portion characterized by a spherical curve or an aspherical curve.
8. The method according to claim 1 , wherein the inner and peripheral echelettes further comprise of transitions characterized by a step height having a value within a range from about 0.5 μm and about 4 μm.
9. The method according to claim 8 , wherein the step heights provide a phase shift between about 0.25 and about 3 times the design wavelength.
10. The method according to claim 8 , wherein the step height for at least 2 echelettes differ.
11. The method according to claim 8 , wherein the surface area for at least 2 echelettes differ.