Method for manufacturing a lens element adapted for correcting an abnormal refraction of an eye of a wearer
Disclosed is a method for manufacturing a lens element intended to be worn in front of an eye of a person, the lens element including two opposite optical faces and a plurality of optical elements each having an optical function of not focusing an image on the retina of the eye of the person so as to slow down the progression of the abnormal refraction of the eye. The method includes: providing a lens blank having at least one unfinished face; and processing the at least one unfinished face to obtain in combination with the opposed optical face a refractive power based on the prescription for the eye of the person and at least a part of the plurality of the optical elements.
1 . A method for manufacturing a lens element configured to be worn in front of an eye of a person, the lens element including two opposite optical faces and a plurality of optical elements each having an optical function of not focusing an image on the retina of the eye of the person to slow down the progression of the abnormal refraction of the eye, the method comprising:
providing a lens blank having at least one unfinished face;
processing at least a part of the plurality of the optical elements having the optical function and the at least one unfinished face to obtain in combination with the opposed optical face a refractive power based on the prescription for said eye of the person,
wherein the optical function is light refraction, and
wherein a part of the at least one unfinished face that provides the refractive power and at least the part of the plurality of the optical elements are realized in a same manufacturing operation.
2 . The method according to claim 1 , wherein the processing of the at least one unfinished face comprises one or more of surfacing, 3D printing, inkjet, and film or patch positioning.
3 . The method according to claim 1 , wherein the at least part of the plurality of optical elements are contiguous.
4 . The method according to claim 1 , wherein the at least one unfinished face is the front or back face of the lens blank.
5 . The method according to claim 1 , wherein at least one of the optical elements has an optical function of focusing an image on a position other than the retina in standard wearing conditions or of not focusing an image in standard wearing conditions.
6 . The method according to claim 1 , wherein at least one of the optical elements has an aspherical surface without a rotational axis of symmetry.
7 . The method according to claim 1 , wherein at least one of the optical elements has a spherical optical function in standard wearing conditions.
8 . The method according to claim 1 , further comprising, prior to the processing:
providing prescription data used to correct the abnormal refraction of the eye of the person;
providing at least one abnormal refraction parameter relating to the abnormal refraction of an eye of the person;
providing at least one sensitivity parameter representing the variation of sensitivity of the person as a function of at least one parameter of the optical elements;
determining a value of the at least one parameter of the optical elements adapted for the person based on the abnormal refraction parameter and the sensitivity parameter; and
determining surface data representing at least one surface of a lens element to be manufactured based at least on the prescription data and the value of the at least one parameter of the optical elements adapted for the person.
9 . The method according to claim 1 , wherein the processing of the at least one unfinished face and at least a part of the plurality of the optical elements are realized in one pass.
10 . The method according to claim 1 , wherein the processing of the at least one unfinished face and at least a part of the plurality of the optical elements are realized successively by processing the at least one unfinished face then by processing the at least a part of the plurality of the optical elements.
11 . The method according to claim 10 , wherein the processing of the at least one unfinished face and at least a part of the plurality of the optical elements are realized in the same frame of reference without unblocking the lens blank.
12 . The method according to claim 1 , wherein the provided lens blank comprises a layer of PMMA disposed on the at least one unfinished surface.
13 . The method according to claim 1 , wherein, after processing, the method comprises polishing the machined surface comprising at least part of the plurality of the optical elements,
wherein one or more of a polishing tool, a polishing speed, and a polishing time is adapted to reduce material removal while maintaining a high level of transparency.
14 . The method of claim 11 , wherein the processing of the at least one unfinished face and at least a part of the plurality of the optical elements are realized by using different tools.
15 . The method according to claim 2 , wherein the at least part of the plurality of optical elements are contiguous.
16 . The method according to claim 2 , wherein the at least one unfinished face is the front or back face of the lens blank.
17 . The method according to claim 3 , wherein the at least one unfinished face is the front or back face of the lens blank.
18 . The method according to claim 2 , wherein at least one of the optical elements has an optical function of focusing an image on a position other than the retina in standard wearing conditions or of not focusing an image in standard wearing conditions.
19 . A lens element configured to be worn in front of an eye of a person, the lens element comprising:
two opposite optical faces; and
a plurality of optical elements having an optical function of not focusing an image on the retina of the eye of the person to slow down the progression of the abnormal refraction of the eye,
wherein at least a part of the plurality of the optical elements are disposed on one of the optical face that in combination with the opposed optical face provides a refractive power based on a prescription for said eye of the person,
wherein the optical function is light refraction, and
wherein a part of the at least one unfinished face that provides the refractive power and at least the part of the plurality of the optical elements are realized in a same manufacturing operation.
20 . The lens element according to claim 19 , further comprising a layer of PMMA on at least one surface comprising at least part of the plurality of optical elements.