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EP-4740060-A1 - OPHTHALMIC LENSES AND METHODS RELATING THERETO

EP4740060A1EP 4740060 A1EP4740060 A1EP 4740060A1EP-4740060-A1

Abstract

An ophthalmic lens (1) and methods (1000) of manufacturing an ophthalmic lens are described. The lens (1) includes an optic zone. The optic zone comprises a central region (5) having a curvature that is centred on an optical axis (19), the central region (5) providing a distance corrective radial curvature power. The central region (5) has a radial sagittal power profile that increases with increasing radial distance from the optical axis (19). The gradient of the radial sagittal power profile across the central region (5) increases with increasing radial distance from the optical axis (19), following a first curve. A first annular region (3) circumscribes the central region (5). The first annular region (3) provides a radial curvature add power.

Inventors

  • WEBBER, MARTIN
  • CHAMBERLAIN, PAUL
  • BRADLEY, ARTHUR
  • ARUMUGAM, Baskar

Assignees

  • CooperVision International Limited

Dates

Publication Date
20260513
Application Date
20241021

Claims (15)

  1. 1. An ophthalmic lens, the lens including an optic zone comprising: a central region having a curvature that is centred on an optical axis, the central region providing a distance corrective radial curvature power, and having a radial sagittal power profile that increases with increasing radial distance from the optical axis, wherein the gradient of the radial sagittal power profile across the central region increases with increasing radial distance from the optical axis, following a first curve; and a first annular region circumscribing the central region, the first annular region providing a radial curvature add power.
  2. 2. An ophthalmic lens according to claim 1, wherein the first annular region has a radial sagittal power profile that increases with increasing radial distance from the optical axis, wherein the gradient of the radial sagittal power profile across the first annular region increases with increasing radial distance from the optical axis, following a second curve.
  3. 3. An ophthalmic lens according to claim 1 or claim 2, further comprising a second annular region circumscribing the first annular region, wherein the second annular region provides a distance corrective radial curvature power and has a radial sagittal power profile that increases with increasing radial distance from the optical axis, wherein the gradient of the radial sagittal power profile across the second annular region increases with increasing radial distance from the optical axis, following the first curve.
  4. 4. An ophthalmic lens according to claim 2 or claim 3, wherein the radial sagittal power increases across the radial width of the first annular region from a first value that lies below the first curve, to a second value that is greater than the first curve.
  5. 5. An ophthalmic lens according to any preceding claim, wherein there is a sharp increase in radial sagittal power at a boundary between the central region and the first annular region.
  6. 6. An ophthalmic lens according to any of claims 1-4, wherein at a point halfway across the radial width of the first annular region, the radial sagittal power lies on the first curve.
  7. 7. An ophthalmic lens according to any of claims 3-6, further comprising a third annular region circumscribing the second annular region, wherein the third annular region provides a radial curvature add power.
  8. 8. An ophthalmic lens according to claim 7, wherein the third annular region has a radial sagittal power profile that increases with increasing radial distance from the optical axis, wherein the gradient of the radial sagittal power profile across the first annular region increases with increasing radial distance from the optical axis following a third curve.
  9. 9. An ophthalmic lens according to any preceding claim, wherein the central region provides an average distance corrective radial curvature power of between +0.5 D and -15.0 D.
  10. 10. An ophthalmic lens according to any preceding claim, wherein the first annular region provides a radial curvature add power that is at least +10.0 D more positive than the average distance corrective radial curvature power.
  11. 11. An ophthalmic lens according to any preceding claim, wherein the central region has a diameter of between about 2.0 and 4.0 mm.
  12. 12. An ophthalmic lens according to any preceding claim wherein the lens is a contact lens.
  13. 13. A contact lens according to claim 12, wherein the lens comprises a hydrogel material, or a silicone hydrogel material, or a combination thereof.
  14. 14. A method of manufacturing an ophthalmic lens, the method comprising: providing a spherical aberration power profile, the spherical aberration power profile being the variation in radial sagittal power for an eye, as a function of radial distance from an optical axis of the eye; providing a target radial sagittal power profile for a lens wearer, the target radial sagittal power profile being the target variation in radial sagittal power as a function of radial distance from an optical axis of the eye of the lens wearer, wherein the target radial sagittal power profile includes a central region having distance corrective radial curvature power, and a first annular region that provides a radial curvature add power; subtracting the spherical aberration power profile from at least the central region of the target radial sagittal power profile, thereby providing a corrected radial sagittal power profile for an ophthalmic lens; and manufacturing an ophthalmic lens having the corrected radial sagittal power profile.
  15. 15. A method according to claim 14, comprising: providing a first spherical aberration power profile that plots variation in radial sagittal power for a lens wearer’s eye when the eye is in a first nonaccommodating state; providing a second spherical aberration power profile that plots variation in radial sagittal power for a lens wearer’s eye when the eye is in a second, accommodating state; subtracting the first spherical aberration power profile from the central region of the target radial sagittal power profile; and subtracting the second spherical aberration power profile from the first annular zone of the target radial sagittal power profile.

Description

OPHTHALMIC LENSES AND METHODS RELATING THERETO Technical Field [0001] The present invention relates to ophthalmic lenses. The present invention relates especially, but not exclusively, to ophthalmic lenses for slowing the progression of myopia. The present invention also relates to methods of manufacturing such lenses. Background [0002] Many people, including children and adults require ophthalmic lenses to correct for myopia (short-sightedness) . [0003] Uncorrected 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. [0004] 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. [0005] In the case of lenses having regions that provide defocus, the regions that provide fullcorrection of distance vision may be referred to as distance corrective regions and the regions that provide under-correction or deliberately induce myopic defocus are usually referred to as myopic defocus regions, treatment 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). [0006] 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 than 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. [0007] 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. [0008] 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 the MISIGHT (CooperVision, Inc.) lenses and other similar lenses described above. In these lenses, the annular region is configured such that no single, on-axis image is formed in front of the retina, thereby preventing such an image from being used to avoid the need for the eye to accommodate near targets. Rather, distant point light sources are imaged by the annular region to a ring-shaped focal line at a near add power focal surface, leading to a small spot size of light, without a surrounding ‘halo’ effect, on the retina at a distance focal surface. [0009] The present disclosure seeks to provide an improved lens for introducing additional myopic defocus, and benefits from the improved image quality enabled by off-axis imaging techniques as