Intra-ocular device with multiple focusing powers/optics
View Patent ↗An intraocular lens device that includes an intraocular lens optics that provides at least two powers of magnification one being near vision power and the other being distance vision power. The lens optics has surface modulations that are responsible for providing the near vision power. The zone structure provides an add power of over 6 diopters. The add power indicative of an extent that the near vision focusing power is greater than the distance vision focusing power.
1. An intraocular lens comprising, an optic that provides at least two powers of magnification, one being near vision power and another being distance vision power, the optic having a plurality of surface modulations configured to achieve add power indicative of an extent that the near vision focusing power is greater than the distance vision focusing power of the optic, the surface modifications providing the add power to be greater than 6 diopters and having a plurality of zones radially spaced from each other.
2. An intraocular lens comprising, an optic that provides at least two powers of magnification, one being near vision power and another being distance vision power, the optic having a plurality of surface modulations within a diffractive zone structure that are configured to achieve light interference for creating add power indicative of an extent that the near vision focusing power is greater than the distance vision focusing power of the optic, the diffractive zone structure providing the add power to be greater than 6 diopters and having a plurality of diffractive zones radially spaced from each other each with at least one of the plurality of surface modulations, the diffractive zone structure being defined as a function of the add power in accord with
r i 2 =(2 i+ 1)λ f
wherein
r i denotes a radial distance of each of the diffractive zones,
i denotes a zone number for which a central zone is denoted by i=0,
λ denotes a design wavelength, and
f denotes an add power.
3. The lens of claim 2 , wherein the optic is either bifocal or multifocal.
4. The lens of claim 2 , wherein the surface modulation is a sawtooth configuration.
5. The lens of claim 4 , wherein the sawtooth configuration has a step height equal to
λ
a
(
n
2
-
n
1
)
f
apodize
wherein
λ denotes the design wavelength
α denotes a parameter that can be adjusted to control diffraction efficiency associated with various orders,
n 2 denotes the index of refraction of the optic,
n 1 denotes the refractive index of a medium in which the lens optics is placed, and
f apodize represents a scaling function whose value decreases as a function of increasing radial distance from an intersection of an optical axis with an anterior surface of the lens optics.
6. The lens of claim 5 , wherein the scaling function f apodize is in accord with
f
apodize
=
1
-
(
r
i
r
out
)
3
wherein
r i denotes the radial distance of an i th zone,
r out denotes an outer radius of a last diffractive zone.
7. The lens of claim 6 , wherein a value of the f apodize is one, a value of α is two.
8. The lens of claim 6 , wherein the diffraction zone structure is formed to resemble a series of ring configurations of different diameters.
9. The lens of claim 2 , wherein the optic is telescopic because of the at least two powers with magnification, further comprising optically aligning the telescopic optic with a non-telescopic optic, the non-telescopic optic lacking multiple powers of magnification.