Lens element
A lens element worn in front of an eye of a person includes a refraction area having a first refractive power based on a prescription for correcting an abnormal refraction of the eye of the person and a second refractive power different from the first refractive power and a plurality of at least three optical elements, at least one optical element having an optical function of not focusing an image on the retina of the eye so as to slow down the progression of the abnormal refraction of the eye.
1. A method for treatment of myopia using a lens element comprising:
obtaining a first refractive power corresponding to a prescription for correcting an abnormal refraction of an eye of a person; and
applying a lens having the first refractive power and a second refractive power, different from the first refractive power, in front of the eye of the person,
wherein the lens includes a plurality of optical elements which defocus an image such that the image is not focused on a retina of the eye, and
wherein a mean sphere of the plurality of optical elements increases from an optical center towards a peripheral part of the lens.
2. The method of claim 1 , wherein the plurality of optical elements are microlenses.
3. The method of claim 1 , wherein the image is substantially unfocused.
4. The method of claim 1 , wherein the step of applying further comprises increasing a defocus of light rays in front the retina of the eye.
5. The method of claim 1 , wherein the second refractive power is greater than the first refractive power.
6. The method of claim 1 , wherein the plurality of optical elements are configured such that along the lens, the mean sphere of the plurality of optical elements increases from a first point towards the peripheral part of the lens by at least 0.5 D, and decreases from a second point towards the peripheral part of the lens by at least 0.5 D, the second point being closer to the peripheral part than the first point.
7. The method of claim 1 , wherein a difference between the first refractive power and the second refractive power is greater than or equal to 0.5 D.
8. The method of claim 1 , wherein the plurality of optical elements are non-contiguous.
9. The method of claim 1 , wherein the step of obtaining the first refractive power corresponding to the prescription for correcting the abnormal refraction of the eye of the person further includes:
determining the first refractive power corresponding to the prescription using a measurement device.
10. The method of claim 1 , wherein the plurality of optical elements are disposed in a substantially circular configuration.
11. The method of claim 1 , wherein the plurality of optical elements are disposed in a ring configuration including at least two rings.
12. The method of claim 1 , wherein the mean sphere is defined as
SPH
mean
=
1
2
(
SPH
min
+
SPH
max
)
,
where
SPH
min
=
(
n
-
1
)
*
CURV
min
=
n
-
1
R
max
,
and
SPH
min
=
(
n
-
1
)
*
CURV
min
=
n
-
1
R
max
.
13. The method of claim 1 , wherein each of the plurality of optical elements is aspherical.
14. The method of claim 1 , wherein at least one of the plurality of optical elements has a contour shape inscribable in a circle having a diameter greater than or equal to 0.8 mm and smaller than or equal to 3.0 mm.