EP-4737104-A1 - METHOD FOR MANUFACTURING AN OPTICAL ARTICLE FOR CONTROLLING EYE-LENGTH RELATED DISORDERS WITH LIGHT FILTERING FUNCTIONS

EP4737104A1EP 4737104 A1EP4737104 A1EP 4737104A1EP-4737104-A1

Abstract

A method for manufacturing an optical article for controlling eye-length related disorders with light filtering functions comprising the steps of: - providing (50) a mold (70) comprising a shaped portion (70a) having a concave micro-structured surface and a smooth portion (70b) having a smooth surface defining a cavity (73); - inserting (52) a light filtering wafer (72) against the concave micro-structured surface (70a); - injecting (56) an optical thermoplastic material (74) into the cavity (73) of the mold (70) via a filler (76), against a back surface of the light filtering wafer (72); - applying a packing pressure via the filler (76) to force more optical thermoplastic material (74) into the mold (70) to compensate for a shrinkage of the optical thermoplastic material (74) during cooling; - opening (58) the mold (70) after the optical thermoplastic material (74) is solidified, thus obtaining an optical article (78) having microstructures (80) on a front surface of the light filtering wafer (72).

Inventors

CHIU, HAO-WEN
CHIU, Alice

Assignees

Essilor International

Dates

Publication Date: 20260506
Application Date: 20241029

Claims (12)

A method for manufacturing an optical article for controlling eye-length related disorders with light filtering functions comprising the steps of: - providing (50) a mold (70) comprising a shaped portion (70a) having a concave micro-structured surface and a smooth portion (70b) having a smooth surface defining a cavity (73); - inserting (52) a light filtering wafer (72) against the concave micro-structured surface (70a); - injecting (56) an optical thermoplastic material (74) into the cavity (73) of the mold (70) via a filler (76), against a back surface of the light filtering wafer (72); - applying a packing pressure via the filler (76) to force more optical thermoplastic material (74) into the mold (70) to compensate for a shrinkage of the optical thermoplastic material (74) during cooling; - opening (58) the mold (70) after the optical thermoplastic material (74) is solidified, thus obtaining an optical article (78) having microstructures (80) on a front surface of the light filtering wafer (72).
The method of claim 1, wherein the light filtering wafer (72) comprises a thermoplastic layer and a light filtering layer.
The method of claim 2, wherein the light filtering layer is polyvinyl alcohol (PVA) or polyethylene terephthalate.
The method of claim 2, wherein the light filtering layer is thermoplastic polyurethane (TPU), polyether block amide (PEBA) or thermoplastic polyol adhesive.
The method of claim 1, wherein the light filtering wafer (72) comprises a thermoplastic layer comprising a light filtering dye.
The method of claim 5, wherein the light filtering dye is blue cut dye, UV cut dye, color enhancement dye, chronocut dye or NIR cut dye.
The method of claims 2 and 5, wherein the thermoplastic layer comprises a material selected from the group consisting of polycarbonate, isosorbide copolycarbonate, thermoplastic polyurethane, polyamide, copolyester, polymethyl methacrylate, methyl methacrylate copolymer, polyethylene terephthalate, polyester, polysulfone, polyphenylsulfone, polyetherimide, cyclic olefin copolymer, cyclic olefin polymer, cellulose triacetate, copolymers thereof, and mixtures thereof.
The method of any of the above claims, wherein the light filtering wafer (72) comprises a polarizing wafer, a photochromic wafer, a blue cut wafer, a UV cut wafer, a color enhancement wafer, a chronocut wafer or a NIR cut wafer.
The method of claim 1, wherein the optical thermoplastic material (74) is selected from the group consisting of polycarbonate, isosorbide copolycarbonate, thermoplastic polyurethane, polyamide, copolyester, polymethyl methacrylate, methyl methacrylate copolymer, polyethylene terephthalate, polyester, polysulfone, polyphenylsulfone, polyetherimide, cyclic olefin copolymer, cyclic olefin polymer, copolymers thereof, and mixtures thereof.
An optical article for controlling eye-length related disorders with light filtering functions manufactured according to a method for manufacturing an optical article for controlling eye-length related disorders with light filtering functions according to any of the claims 1 to 9.
The optical article of claim 10, wherein the optical article comprises at least one of a finished lens, a semi-finished lens, a wafer or a film.
The optical article of claim 11, designed for controlling myopia of an individual.

Description

Technical field This invention relates to a method for manufacturing an optical article for controlling eye-length related disorders with light filtering functions, for example an optical article that comprises polar or photochromic filtering functions, for myopia control. Background information and prior art Ophthalmic lenses for controlling eye-length related disorders, for example for controlling myopia, are nowadays produced as clear lenses. Figure 1 shows the step of a known injection molding method for producing such lenses. In a first step 2, a mold 10 comprising a shaped portion 10a having a micro-structured surface being maintained at a first temperature Tmold,a and a smooth portion 10b having a smooth surface being maintained at a second temperature Tmold,b is provided, wherein the first temperature Tmold,a and the second temperature Tmold,b are the same or different. In a second step 4, a molten optical thermoplastic material 12 at a melt temperature Tmelt is injected under pressure into the mold 10 through a filler 14, wherein the melt temperature Tmelt is higher than the glass transition temperature Tg of the optical thermoplastic material 12. The glass transition temperature Tg is the temperature at which a polymer changes from a hard, glassy state to a soft, rubbery state, or vice versa. Both the first temperature Tmold,a and the second temperature Tmold,b are lower than the glass transition temperature Tg of the optical thermoplastic material 12 allowing the molten optical thermoplastic material 12 injected in the second step 4 to cool down and solidify. Finally, in a third step 6, the mold 10 is opened after the optical thermoplastic material 12 is sufficiently solidified to hold its shape, thus allowing obtaining a lens 16 having microstructures (microlenses) 18 on a front convex surface (a micro-structured surface). The micro-structured surface allows obtaining peripheral defocus of light impinging on the retina of a user wearing such lenses, thus controlling the progression of myopia. In the present of the description reference will be made to a "lens", however, other known optical such as wafers or films can be considered. In the present description reference will be made to controlling myopia, however, other known eye-length related disorders can be considered. Children are recommended to wear these types of lenses for a minimum of twelve hours a day for getting the best results, and this entails wearing the lens also to attend outdoor activities when strong sunlight may be present, which may lead to a potential risk of photophobia. Furthermore, it is known that extended exposure to UV can result in long term damage to the retina or even cataract over the years. In addition, children may be exposed, during their daily activities, to other potentially damaging light sources such as blue light. Accordingly, there is the need to provide an innovative method for manufacturing an optical article for controlling eye-length related disorders, such as myopia, that offers at the same time light filtering functions, for example to get protection to the eyes from strong sunlight or to provide extra protection to the eyes through other light filtering functions such as blue cut, chronocut or NIR cut, thus overcoming the problems of the prior art. Summary What is provided herein is a method for manufacturing an optical article for controlling eye-length related disorders with light filtering functions comprising the steps of: providing a mold comprising a shaped portion having a concave micro-structured surface and a smooth portion having a smooth surface defining a cavity;inserting a light filtering wafer against the concave micro-structured surface;injecting an optical thermoplastic material into the cavity of the mold via a filler, against a back surface of the light filtering wafer;applying a packing pressure via the filler to force more optical thermoplastic material into the mold to compensate for a shrinkage of the optical thermoplastic material during cooling;opening the mold after the optical thermoplastic material is solidified, thus obtaining an optical article having microstructures on a front surface of the light filtering wafer. In an embodiment, the light filtering wafer comprises a thermoplastic layer and a light filtering layer. In an embodiment, the light filtering layer is polyvinyl alcohol (PVA) or polyethylene terephthalate. In an embodiment, the light filtering layer is thermoplastic polyurethane (TPU), polyether block amide (PEBA) or thermoplastic polyol adhesive. In an embodiment, the light filtering wafer comprises a thermoplastic layer comprising a light filtering dye. In an embodiment, the light filtering dye is blue cut dye, UV cut dye, color enhancement dye, chronocut dye or NIR cut dye. In an embodiment, the thermoplastic layer comprises a material selected from the group consisting of polycarbonate, isosorbide copolycarbonate, thermoplastic polyurethane, polyamide, co