US-12625390-B2 - Contact lenses and methods relating thereto

US12625390B2US 12625390 B2US12625390 B2US 12625390B2US-12625390-B2

Abstract

A contact lens ( 2001 ) and methods of manufacturing such a lens ( 2001 ) are described. The contact lens ( 2001 ) comprises an optic zone ( 202 ). The optic zone ( 202 ) comprises a central portion having a centre of curvature that is on an optical axis ( 219 ), and a first annular portion ( 203 ) extending radially outwards from the central portion ( 205 ). The first annular portion ( 203 ) provides a curvature add power. One of an anterior surface and a posterior surface of the first annular portion ( 203 ) has a centre of curvature that is on the optical axis ( 219 ). The other of the anterior surface and the posterior surface of the first annular portion ( 203 ) has a centre of curvature that is separated by a first distance from the optical axis ( 219 ).

Inventors

Caeli QUITER
Martin WEBBER

Assignees

COOPERVISION INTERNATIONAL LIMITED

Dates

Publication Date: 20260512
Application Date: 20240719

Claims (20)

1 . A contact lens comprising an optic zone, the optic zone comprising: a central portion having a centre of curvature that is on an optical axis; and a first annular portion extending radially outwards from the central portion, wherein the first annular portion provides a radial curvature add power, and wherein one of an anterior surface and a posterior surface of the first annular portion has a centre of curvature that is on the optical axis, and the other of the anterior surface and the posterior surface of the first annular portion has a centre of curvature that is separated by a first distance from the optical axis; and wherein the surface of the first annular portion having the centre of curvature that is on the optical axis provides a radial curvature add power of between +0.5 D and +4.0 D, and the surface of the first annular portion having the centre of curvature that is separated by a first distance from the optical axis provides a radial curvature add power of between +4.0 D and +20.0 D.
2 . The contact lens according to claim 1 , wherein the surface of the first annular portion having the centre of curvature that is separated by the first distance from the optical axis has a radial sagittal power profile that increases with increasing radial distance from the optical axis.
3 . The contact lens according to claim 1 , wherein the surface of the first annular portion having the centre of curvature that is separated by the first distance from the optical axis has a radial sagittal power profile that is defined by a line with a gradient of between 1.0 D/mm and 6.0 D/mm, or a curve with an average gradient of between 1.0 D/mm and 6.0 D/mm.
4 . The contact lens according to claim 1 , wherein the surface of the first annular portion having the centre of curvature that is separated by the first distance from the optical axis has an average radial sagittal add power of zero across the radial width of the first annular portion.
5 . The contact lens according to claim 1 , wherein, for the surface of the first annular portion having the centre of curvature that is separated by the first distance from the optical axis, the radial sagittal power at an inner edge of the first annular portion is between 0.5 D and 2.5 D less than the radial sagittal power at an outer edge of the central portion.
6 . The contact lens according to claim 5 , wherein, for the surface of the first annular portion having the centre of curvature that is separated by the first distance from the optical axis, the radial sagittal power at an outer edge of the first annular region is between 0.5 D and 2.0 D greater than the radial sagittal power at an outer edge of the central portion.
7 . The contact lens according to claim 1 , wherein both the anterior surface and the posterior surface of the first annular portion provide a radial sagittal add power that is greater than zero across the radial width of the first annular portion.
8 . The contact lens according to claim 1 , wherein the first annular portion has an average radial sagittal add power of between +0.5 D and +6.0 D.
9 . The contact lens according to claim 1 , wherein the first annular portion has a radial sagittal power profile that increases with increasing radial distance from the optical axis.
10 . The contact lens according to claim 9 , wherein the first annular portion has a radial sagittal power profile that is defined by a line with a gradient of between 0.5 D/mm and 5.0 D/mm, or a curve with an average gradient of between 0.5 D/mm and 5.0 D/mm.
11 . The contact lens according to claim 1 , wherein the first annular portion has an average radial curvature power of between +4.5 D and +24.0 D.
12 . The contact lens according to claim 1 , further comprising at least one additional annular portion that is concentric to the first annular portion, wherein each additional annular portion provides a radial curvature add power, and wherein for each additional annular portion one of an anterior and a posterior surface of that portion has a centre of curvature that is on the optical axis, and the other of the anterior and the posterior surface of that portion has a centre of curvature that is separated by a distance from the optical axis.
13 . The contact lens according to claim 12 , wherein the radial sagittal power gradient of each additional annular portion is dependent upon the radial position of the annular portion.
14 . The contact lens according to claim 12 , wherein a first annular portion has a radial sagittal power profile that increases with increasing radial distance from the optical axis with a first gradient, and a second annular portion has a radial sagittal power profile that increases with increasing radial distance from the optical axis with a second gradient that is smaller than the first gradient.
15 . The contact lens according to claim 12 , further comprising a plurality of concentric additional annular portions, wherein the additional annular portions are separated by distance portions having a base radial curvature power.
16 . The contact lens according to claim 1 , wherein the first annular portion extends radially outwards from a perimeter of the central region by between 0.5 and 1.5 mm.
17 . The contact lens according to claim 1 , wherein the lens comprises an elastomer material, a silicone elastomer material, a hydrogel material, or a silicone hydrogel material, or mixtures thereof.
18 . A method of manufacturing a contact lens the method comprising: forming the contact lens according to claim 1 .
19 . The method according to claim 18 , further comprising: providing a female mold member with a concave lens forming surface; and providing a male mold member with a convex lens forming surface, wherein one of the concave and convex lens forming surfaces is configured to produce the first annular portion having the centre of curvature that is separated by the first distance from the optical axis of the lens; and the other of the concave and convex lens forming surfaces is configured to produce the first annular portion having the centre of curvature that is on the optical axis of the lens; and using the female and male mold members to form the lens.
20 . The method according to claim 19 , further comprising: cast molding the lens using the male mold member and the female mold member.

Description

This application claims the benefit under 35 U.S.C. § 119(e) of prior U.S. Provisional Patent Application No. 63/528,655, filed Jul. 25, 2023, which is incorporated in its entirety by reference herein. The present invention relates to contact lenses. The present invention relates especially, but not exclusively, to contact lenses for slowing the progression of myopia. The present invention also relates to methods of manufacturing such lenses. BACKGROUND Many people, including children and adults require contact lenses to correct for myopia (short-sightedness). Myopic eyes focus incoming light from distant objects to a location in front of the retina. Consequently, the light converges towards a plane in front of the retina and diverges towards, and is out of focus upon arrival at, the retina. Conventional lenses (e.g., spectacle lenses and contact lenses) for correcting myopia reduce the convergence (for contact lenses), or cause divergence (for spectacle lenses) of incoming light from distant objects before it reaches the eye, so that the location of the focus is shifted onto the retina. It was suggested several decades ago that progression of myopia in children or young people could be slowed or prevented by under-correcting, i.e., moving the focus towards but not quite onto the retina. However, that approach necessarily results in degraded distance vision compared with the vision obtained with a lens that fully corrects for myopia. Moreover, it is now regarded as doubtful that under-correction is effective in controlling developing myopia. A more recent approach to correct for myopia is to provide lenses having both one or more regions that provide full correction of distance vision and one or more regions that under-correct, or deliberately induce, myopic defocus. It has been suggested that this approach can prevent or slow down the development or progression of myopia in children or young people, whilst providing good distance vision. In the case of lenses having regions that provide defocus, the regions that provide full-correction of distance vision are usually referred to as base power regions and the regions that provide under-correction or deliberately induce myopic defocus are usually referred to as myopic defocus regions or add power regions (because the dioptric power is more positive, or less negative, than the power of the distance regions). A surface (typically the anterior surface) of the add power region(s) has a smaller radius of curvature than that of the distance power region(s) and therefore provides a more positive or less negative power to the eye. The add power region(s) are designed to focus incoming parallel light (i.e., light from a distance) within the eye in front of the retina (i.e., closer to the lens), whilst the distance power region(s) are designed to focus light and form an image at the retina (i.e., further away from the lens). A known type of contact lens that reduces the progression of myopia is a dual-focus contact lens, available under the name of MISIGHT (CooperVision, Inc.). This dual-focus lens is different to bifocal or multifocal contact lenses configured to improve the vision of presbyopes, in that the dual-focus lens is configured with certain optical dimensions to enable a person who is able to accommodate to use the distance correction (i.e., the base power) for viewing both distant objects and near objects. The treatment zones of the dual-focus lens that have the add power also provide a myopically defocused image at both distant and near viewing distances. Whilst these lenses have been found to be beneficial in preventing or slowing down the development or progression of myopia, annular add power regions can give rise to unwanted visual side effects. Light that is focused by the annular add power regions in front of the retina diverges from the focus to form a defocused annulus at the retina. Wearers of these lenses therefore may see a ring or ‘halo’ surrounding images that are formed on the retina, particularly for small bright objects such as street lights and car headlights. Also, rather than using the natural accommodation of the eye (i.e., the eye's natural ability to change focal length) to bring nearby objects into focus, in theory, wearers can make use of the additional focus in front of the retina that results from the annular add power region to focus near objects; in other words, wearers can inadvertently use the lenses in the same manner as presbyopia correction lenses are used, which is undesirable for young subjects. For treating myopia, it is recognised that it may be beneficial to provide a lens that introduces additional myopic defocus. For treating presbyopia, it may be beneficial to provide a lens that gives rise to an extended depth of focus. Further lenses have been developed which can be used in the treatment of myopia, and which are designed to eliminate the halo that is observed around focused distance images. In these lenses, the an