WO2020202081A1

WO2020202081A1 - Contact lens and method to prevent myopia progression

Info

Publication number: WO2020202081A1
Application number: PCT/IB2020/053178
Authority: WO
Inventors: Martin Loertscher
Original assignee: Myopiaok Gmbh; Phillips, John Robert
Priority date: 2019-04-04
Filing date: 2020-04-03
Publication date: 2020-10-08

Abstract

A contact lens has a body with a central region and a surrounding annular region. The central region has a first optical surface area having a first negative focal power, which creates a first focal point on a first optical axis of the first optical surface area. The annular region has an annular optical surface area having a second negative focal power, the second negative focal power being less negative than the first negative focal power. The annular region is configured to create an annular focal region about the first optical axis, wherein a second focal plane corresponding to the annular focal region is perpendicular to the first optical axis.

Description

Contact lens and method to prevent myopia progression

Background

The present invention relates generally to the prevention of myopia progression, and more specifically to a contact lens and a method to prevent myopia progression.

Myopia (also called short-sightedness or nearsightedness) is a common ocular condition in which distant objects appear blurred whereas near objects are seen clearly. The prevalence of myopia, which is about 25% in developed countries and may be 70-80% in parts of Asia, has significant socioeconomic and public health consequences. Even people with relatively low degrees of myopia usually require an optical correction (for example spectacles or contact lenses) to allow them to drive a car or see the school blackboard, whereas those with high myopia also have an increased risk of developing blinding conditions such as retinal detachment and glaucoma. Myopia often develops during childhood and typically increases in severity (requiring progressively stronger spectacles to correct it) until early adulthood, although the final amount of myopia that develops will vary between individuals.

Myopia is generally characterised by an abnormal enlargement of the eye-ball which has the effect of moving the light-sensitive tissue (the retina in the back of the eye) out of the focal plane of the optical components of the eye. Thus, images of distant objects are brought to focus in front of the retina, rather than in the plane of the retina. Images of distant objects are therefore seen as blurred. In high levels of myopia, the marked enlargement of the eye-ball also results in a stretching of the retina and its associated blood supply, which renders the eye more susceptible to retinal detachment, glaucomatous damage and degenerative myopic retinopathy.

The aetiology of myopia is poorly understood. Both genetic and environmental factors have been implicated. However, it is known from animal experiments that exposing the eye to extended periods of hyperopic retinal defocus (image plane located posterior to the retina) induces eye growth and the development of myopia. In contrast, exposing the eye to extended periods of myopic retinal defocus (image plane located anterior to the retina) slows eye growth and inhibits the development and progression of myopia. In susceptible individuals myopia progression is thought to be associated with excessive near work (for example reading, writing/drawing, playing video games, and similar activities). This is possibly because the prolonged muscular effort of focussing the eyes at near (accommodation) results in a lag of accommodation (insufficient accommodation) and hyperopic retinal de-focus. In contrast, individuals who spend extended periods of time outdoors (where most objects are present at a significant distance from the eye) have a lower incidence of myopia. It has been suggested that this may result from a lead of accommodation, leading to extended periods of myopic retinal defocus.

International patent application W02006/004440 discloses a method and contact lens for prevention of myopia progression. The contact lens includes a vision correction area for correcting in use the myopic vision of a wearer to present a clear image to the wearer during distance viewing, and during near viewing with accommodation by the eye during near viewing. The contact lens also includes a myopic defocus area to also simultaneously present a myopic defocused image during both distance and near viewing (with accommodation by the eye during near viewing). The myopic retinal de-focus inhibits the abnormal axial elongation of the eyes that underlies myopia progression, with the effect that over time the progression of myopia slows, stops, or reverses.

Figure 1 shows a prior art contact lens T on an eyeball 2’ of a myopic wearer. The prior art contact lens T has a central vision correction zone 3’ configured to correct existing myopic vision of the wearer. Accordingly, when the prior art lens T is worn by the wearer, the focal point Fc’ created by the correction zone 3’ lies on or at least near a retinal surface 25’ of the eyeball 2’, on an optical axis Ai’ of the prior art contact lens T, thus creating a focused image on the retinal surface 25’.

The prior art contact lens T further comprises a treatment zone 4’ which may be circumferentially arranged around the vision correction zone 3’. The focal length of the treatment zone 4’ is shorter than the focal length of the correction zone 3’, thus a focal point F ’ created by the treatment zone 4’ meets the optical axis AT anterior to the retinal surface 25’, as can be seen in the lower part of Figure 1. Accordingly, as the person of ordinary skill will further take from the Figure, the treatment zone 3’ creates a defocused image on the retinal surface 25’, which is believed to be effective to at least slow myopia progression. While the prior art contact lens T described in the foregoing has proved to be effective in the treatment of myopia, cases have been reported in which patients complained about what has been referred to as a“ghosting” while wearing the prior art contact lens 1’, which phenomenon is characterised by blurred image boundaries under certain light conditions.

The inventor of the present invention believes that the ghosting phenomenon is at least partially caused by the superposition of the defocused and focused image on the retinal surface 25’, effected by the correction zone 3’ and the treatment zone 4’.

Brief Summary of the Invention

According to one aspect of the invention, there is provided a contact lens having a body, the body comprising a central region and at least one annular region surrounding the central region, wherein the central region has a first optical surface area having a first negative focal power, the first optical surface area being configured to create a first focal point on a first optical axis of the first optical surface area; the annular region has an annular optical surface area having a second negative focal power, the second negative focal power being less negative than the first negative focal power; the annular region is configured to create an annular focal region about the first optical axis, wherein a second focal plane corresponding to the annular focal region is perpendicular to the first optical axis.

Preferably, the annular focal region is radially spaced apart from the first optical axis by a distance d1 , the distance d1 ranging between 0.1 mm < d1 < 2.0 mm.

Preferably, a first focal plane corresponding to the first focal point and the second focal plane are spaced apart by a distance d2 along the first optical axis, the distance d2 ranging between 0.1 mm < d2 < 1.5 mm. Preferably, the annular region comprises at least one refractive optical element in series with the annular optical surface area and cooperating with the annular optical surface area to form the annular focal region.

Preferably, the refractive optical element is embedded in the body of the contact lens between the annular optical surface area and a back surface of the contact lens.

Preferably, the refractive optical element is integrally formed with the contact lens.

Preferably, the refractive optical element is formed as part of the optical surface area.

Preferably, the refractive optical element is formed as part of the back surface of the contact lens. Preferably, the refractive optical element is formed as parts of both the annular optical surface area and the back surface of the contact lens.

Preferably, the refractive optical element is an annular radial prism.

Preferably, the annular radial prism is arranged‘base out’ in the annular region, with an apex of the annular radial prism pointing towards the first optical axis. Preferably, the annular radial prism is arranged‘base in’ in the annular region with an apex of the annular radial prism pointing away from the first optical axis.

Preferably, the second negative focal power is up to 5 dioptres less negative than the first negative focal power.

Preferably, a diameter of the first optical surface area is at least 3.0 mm. Preferably, an outer diameter of the annular optical surface area is at least 4.0 mm.

Preferably, the annular region comprises a second refractive optical element in series with the annular optical surface area and the first refractive optical element, the second refractive optical element being configured to translate the annular focal region relative to the first axis . Preferably, the body comprises one or more additional annular regions concentrically surrounding the first annular region, each of the one or more additional annular regions having a corresponding additional annular optical surface area having a corresponding negative focal power, each of the corresponding negative focal powers being less negative than the first negative focal power.

Preferably, each of the one or more additional annular regions comprises at least one refractive optical element in series with the corresponding additional annular optical surface area and cooperating with the corresponding additional annular optical surface area to form an additional annular focal region. Preferably, the contact lens is a disposable lens, in particular a daily disposable lens or a monthly disposable lens.

According to another aspect of the invention, there is provided a method of treating or slowing the progression of myopia in a person, the method comprising: applying to the eye or eyes of the person or prescribing for the person, a contact lens or lenses, each contact lens having a body, the body comprising a central region and at least one annular region surrounding the central region, wherein the central region has a first optical surface area having a first negative focal power, the first optical surface area being configured to create a focused image on or near a retinal surface of the eye, to correct the myopia; the annular region has an annular optical surface area having a second negative focal power, the second negative focal power being less negative than the first negative focal power; the annular region is configured to create an annular focal region located anterior to the retinal surface, thus creating an annular region of defocus on the retinal surface . Preferably, the annular region comprises a refractive optical element in series with the annular optical surface area and cooperating with the annular optical surface area to form the annular focal region .

Preferably, the first negative focal power and the second negative focal power ranges between 0.5 and 5.0 dioptres.

The invention may also be said to consist in any new features or combinations of features disclosed herein. Those skilled in the art to which the invention relates will appreciate that further aspects of the invention will become apparent from the following disclosure.

Brief Description of the Drawing Figures

Figure 1 shows a sectional view of an eyeball and a contact lens according to the prior art, and optical paths related thereto;

Figure 2A shows a sectional view of an eyeball and a contact lens according to an embodiment of the invention, and optical paths related thereto; Figure 2B shows a sectional view of an eyeball and a contact lens according to an embodiment of the invention, and optical paths related thereto; Figure 3A shows a point spread function derived from measures in a myopic person wearing a contact lens according to the prior art;

Figure 3B shows a point spread function derived from measures in a myopic person wearing a contact lens according to an embodiment of the invention;

Figure 4A shows a simulated retinal image of the letter Έ” as seen through the prior art contact lens of Figure 1 , derived from the point spread function shown in Figure 3A; and

Figure 4B shows a simulated retinal image of the letter Έ” as seen through a contact lens according to an embodiment of the invention, derived from the point spread function shown in Figure 3B;

Description of Preferred Embodiments or Examples of the Invention

Figure 2 shows a contact lens 1 according to an embodiment of the present invention, on the eyeball 2 of a myopic wearer or patient. It will be appreciated that in at least some embodiments of the invention, the contact lens 1 is a disposable lens, in particular a daily disposable lens or a monthly disposable lens, while in other embodiments contact lens 1 is non-disposable, also called a reusable contact lens. The contact lens 1 has a body comprising a central region 10 and at least one annular region 20 surrounding the central region 10.

The central region 10 has a first optical surface area 12 which in turn has a first negative focal power. The first optical surface area 12 has an optical axis

which is depicted in the lower part of Figure 2. The first optical surface area 12 is configured to create a first focal point 14 on the first optical axis Ai.

In a method of treating myopia according to an embodiment of the invention, the first negative focal power is configured to create a focused image on or near a retinal surface 25 of the eye, to correct the myopia. Generally speaking, the best correction of the myopia can be achieved when the focal length of the first optical surface area 12 is chosen such that a first focal plane 23 corresponding to the first focal point 14 coincides with the retinal surface 25 in the first focal point 14, which ideally corresponds to the location of the fovea of the eye 1 .

The annular region 20 has an annular optical surface area 22 which has a second negative focal power. In contrast to the prior art, and as can be seen in Figure 2, the annular region 20 of the inventive contact lens 1 creates an annular focal region 24 about the first optical axis Ai.

In embodiments of the invention, a diameter Di of the first optical surface area 12 is at least 3.0 mm. Further, in some embodiments of the invention, an outer diameter (D₀) of the annular optical surface area 22 is at least 4.0 mm.

The annular focal region 24 lies on a second focal plane 26 which is perpendicular to the first optical axis Ai . The skilled person will appreciate in the light of Figure 2 that the second negative focal power is less negative than the first negative focal power, and hence the first focal plane 23 and the second focal plane 26 are spaced apart by a distance d2 along the first optical axis Ai.

Accordingly, in a method of treating myopia according to the invention, when the first optical surface area 12 is configured to correct the myopia of the patient, the annular focal region 24 created by the annular region 20 of the contact lens 1 is located anterior to the retinal surface 25 of the wearer, thus creating an annular region of defocus 27 on the retinal surface 25.

As a consequence, the first optical surface area 12 in the contact lens 1 according to the invention corrects in use the myopic vision of a wearer to present a clear image to the wearer during distance viewing, and during near viewing with accommodation by the eye, while the annular optical surface area 22 simultaneously presents a myopic defocused image during both distance and near viewing (with accommodation by the eye during near viewing).

Moreover, both the contact lens 1 and the method of treating myopia according to the invention overcome the problems of the prior art related to what has been referred to as ‘ghosting’ of vision, as will be described in more detail with reference to Figures 3 and 4.

Figure 3 includes a comparison of certain optical characteristics of the prior art contact lens 1’ and the contact lens 1 according to the present invention, on the basis of so-called point spread functions (PSF) of each optical system.

The PSF shown in Figure 3 were derived from measures in a myopic person. PSF 60’ shown in Figure 3A was derived while the person was wearing the prior art lens T, and PSF 60 shown in Figure 3B was derived while the person was wearing a contact lens according to an embodiment of the invention.

As the skilled person will appreciate, the PSF 60’, 60 shown in Figures 3A and 3B represent the intensity of light on the image plane x, y for a point light source with spherical, outwards travelling wave fronts. For the sake of completeness, it should be mentioned that in both cases, the units in the x-z-scale represent 10 arcmin.

The PSF 60’ shown in Figure 3A and referring to the prior art contact lens T exhibits a distinct tip portion 6T in the centre of the image plane x, y, and a base portion 62’. The shape of the PSF 60’ can further be characterised by means of the so-called Strehl ratio, which is known in the art and can broadly be said to correspond to the ratio of the peak intensity of a measured point spread function to the peak intensity of a perfect diffraction- limited PSF for the same optical system. The PSF 60’ in Figure 3a has a Strehl ratio of 0.1 16.

Compared thereto, the PSF 60 of the contact lens 1 according to the invention, which is shown in Figure 3B, has a base portion 62 which is much wider in the image plane x, y in relation to its tip portion 61 , and has a Strehl ratio of 0.035. Taking into account that a higher Strehl ratio indicates increased optical quality, with maximum value of 1.00, at first glance the optical characteristics of the inventive contact lens 1 thus seem to be inferior to the prior art lens T.

However, as those skilled in the art will appreciate in the light of Figure 3B, rather than by an inferior optical quality, the lower Strehl ratio in this case is actually caused by a particular, favourable shape of the intensity distribution, which exhibits a distinct annular gap 64 of very low intensity in the PSF 60, extending around the central region of the PSF 60. This annular gap 64 is caused by the annular focal region 24 and reflects that, as a result of the features of the contact lens 1 according to the invention, the clear image created by the first optical surface area 12 and the defocused image created by the annular optical surface area 22 are spatially separated. This results in less blur of the myopia corrected image, as will be discussed in more detail with reference to Figure 3 further below. The skilled person will appreciate that the shape of the PSF 60 is an objective indicator that the contact lens 1 according to the invention reduces the phenomenon of ghosting of vision.

The width of the annular gap 64 may be adjusted by the geometry of the body of the contact lens 1 , and is particularly dependent on the position of the annular focal region 24 in relation to the first focal point 14. In preferable embodiments of the invention, the annular focal region 24 is radially spaced apart from the first optical axis

by a distance di ranging between 0.1 mm < di < 2.0 mm, as indicated in Figure 2.

The effects described in the above will now be further explained in more detail with reference to Figure 4.

Figure 4 includes a comparison of a simulated retinal image of the letter Έ” as seen through the prior art contact lens T of Figure 1 and through the contact lens 1 according to the invention. The simulation results shown in Figure 4 have been derived on the basis of the measured PSF 60’ and, respectively, 60 discussed in the context of Figure 3.

The skilled person will appreciate that Figure 4A, which represents the vision with the prior art contact lens T, shows a blurred region 40’ centred around an area 50’ of higher contrast. The area 50’ of higher contrast corresponds to the vision correction effected by the correction zone 3’ of the prior art contact lens T and has, accordingly, highly defined boundaries which are however not identifiable in Figure 4A due to the superposition of this image with the blurred region 40’.

The blurred region 40’ corresponds to the defocused image on the retinal surface 25’ discussed in context with Figure 1 and is believed to stop or at least slow down myopia progression.

It is furthermore believed that the superposition of the area 50’ of higher contrast and the blurred region 40’ cause the ghosting of vision irritating certain wearers of the prior art contact lenses 1 , with the points Ft’ and Fc’ (see Figure 1), when projected onto the retinal surface 25’, coinciding on the optical axis Ai’.

Turning to Figure 4B, which represents the simulated retinal image with the inventive contact lens 1 , the skilled person will appreciate that a blurred region 40 shown in this Figure is less likely to interfere with an area 50 of higher contrast, which more clearly represents the letter Έ” when compared to Figure 4A.

In contrast to what is known from the prior art, the contact lens 1 according to the invention creates an annular focal region 24 about the first optical axis Ai, which means that the projection of the focal region 24 onto the retinal surface 25, and similarly the annular region of defocus 27 is spread out, away from the focal point 14.

The skilled person will appreciate in the light of Figures 3 and 4 that the annular region of myopic defocus 27, while being effective in slowing down the progress of myopia in the patient, at the same time reduces the ghosting of vision effect present in the prior art.

In order to effect the annular shape of the annular focal region 24, in embodiments of the invention, the annular region 20 comprises a refractive optical element 30 in series with the annular optical surface area 22 and cooperating with the annular optical surface area 22 to form the annular focal region 24. Suitable refractive optical elements comprise, inter alia, annular radial prisms and/or a slab prisms.

The lower parts of Figures 2A and 2B, respectively, show embodiments of the invention using an annular radial prism 30 in series with the annular optical surface area 22. In the depicted embodiments, the annular radial prism 30 is embedded in the body of the contact lens 1 between the annular optical surface area 22 and a back surface 36 of the contact lens 1 . Generally speaking however, and not limited to the type of the refractive optical element, multiple ways of including the refractive optical element in the body of the contact lens 1 are envisaged for the purposes of the invention. For example, the refractive optical element 30 can be integrally formed with the contact lens 1 , formed as part of the optical surface area 22, formed as part of the back surface 36 of the contact lens 1 , and/or formed as parts of both the optical surface area 22 and the back surface 36 of the contact lens 1 .

As can be taken from Figures 2A and 2B, respectively, parallel light rays 100 entering the contact lens 1 are convergently refracted by annular optical surface area 22, and subsequently deflected by the annular radial prism 30 to form an annular focal region 24. In the embodiment shown in Figure 2A, due to the orientation of the annular radial prism 30‘base out’ in the annular region 20, with an apex 31 of the annular radial prism 30 pointing towards the first optical axis Ai, the light is radially deflected in a direction away from the first axis

before it converges on the second focal plane 26. This embodiment may be advantageous in that the annular radial prism 30 in the‘base out’ configuration does not require to have a high refractive power to redirect the light to create the desired annular focal region 24 with a sufficient radial distance di to the optical axis Ai.

In the embodiment shown in Figure 2B, the annular radial prism 30 is arranged‘base in’ in the annular region 20, with the apex 31 of the annular radial prism 30 pointing away from the first optical axis Ai. Accordingly, light passing through the annular optical surface area 22 and entering the annular radial prism 30 on a converging path is radially deflected in a direction towards the first axis Ai. In this embodiment, the light rays 100 intersect the first optical axis

at a point 28 before they form the annular focal region 24 on the second focal plane 26. Compared to the‘base out’ alternative, the annular radial prism 30 in this configuration requires to have a higher refractive power, because the light must be redirected through a greater angle, which will be appreciated in the light of Figure 2B. Flowever, this embodiment may be advantageous in that the orientation of the annular radial prism 30, which is characterised by less material at the outer periphery, would follow the general shape of the contact lens 1 , which exhibits a decrease of its overall thickness towards its outer periphery as well, in order to make it more comfortable to wear.

In both the embodiment of Figure 2A and the one shown in Figure 2B, and depending on the application or therapy, the difference between the first negative power and the second negative power can range between 0.5 to 5.0 dioptres in embodiments of the invention, corresponding to a distance d2 between the first 23 and second focal plane 26 ranging between 0.1 mm < d2 < 1.5 mm, see lower part of Figures 2 and 3, respectively.

In some embodiments of the invention, the centre of the annular focal region 24 has an offset from the first optical axis Ai, in the sense of a shift or a translation, which the inventors believe to help achieving a clearer distinction between the area 50 of higher contrast and the blurred region 40. To this end, the annular region 20 may comprise a second refractive optical element in series with the annular optical surface area 22 and the first refractive optical element 30. The second refractive optical element can be an annular slab prism which is configured to translate the annular focal region 24 relative to the first axis Ai. The offset of the centre of the annular focal region 24 and the first focal point 14 is believed to be beneficial in the reduction of the phenomenon of ghosting of vision. In embodiments of the invention, the first refractive optical element 30 and the second refractive optical element can be combined in a single hybrid optical element.

In further embodiments, the body of the contact lens 1 comprises one or more additional annular regions concentrically surrounding the first annular region 20, each of the one or more additional annular regions having a corresponding additional annular optical surface area having a corresponding negative focal power, and each of the corresponding negative focal powers being less negative than the first negative focal power. This way, multiple regions of myopic defocus can be effected, wherein the degree of defocus of each of the regions of myopic defocus can individually be set.

The skilled person will appreciate that on top of that, each of the one or more additional annular regions can comprise at least one or more refractive optical elements in series with the corresponding additional annular optical surface area, cooperating with the corresponding additional annular optical surface area to translate the corresponding region of myopic defocus into an annular focal region of myopic defocus, with the advantages of a clear focused image with minimum ghosting effect.

Unless the context clearly requires otherwise, throughout the description and the claims, the words“comprise”,“comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of“including, but not limited to”. Where in the foregoing description, reference has been made to specific components or integers of the invention having known equivalents, then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the spirit or scope of the appended claims.

Claims

1. A contact lens having a body, the body comprising a central region and at least one annular region surrounding the central region, wherein

the central region has a first optical surface area having a first negative focal power, the first optical surface area being configured to create a first focal point on a first optical axis of the first optical surface area;

the annular region has an annular optical surface area having a second negative focal power, the second negative focal power being less negative than the first negative focal power;

the annular region is configured to create an annular focal region about the first optical axis, wherein a second focal plane corresponding to the annular focal region is perpendicular to the first optical axis.

2. The contact lens according to claim 1 , wherein the annular focal region is radially spaced apart from the first optical axis by a distance d-i, the distance di ranging between 0.1 mm < di < 2.0 mm.

3. The contact lens according to any of claims 1 or 2, wherein a first focal plane corresponding to the first focal point and the second focal plane are spaced apart by a distance d2 along the first optical axis, the distance d2 ranging between 0.1 mm < d2 < 1.5 mm.

4. The contact lens according to any previous claim, wherein the annular

region comprises at least one refractive optical element in series with the annular optical surface area and cooperating with the annular optical surface area to form the annular focal region.

5. The contact lens according to claim 4, wherein the refractive optical

element is embedded in the body of the contact lens between the annular optical surface area and a back surface of the contact lens.

6. The contact lens according to any of claims 4 or 5, wherein the refractive optical element is integrally formed with the contact lens.

7. The contact lens according to any of claims 4 to 6, wherein the refractive optical element is formed as part of the optical surface area.

8. The contact lens according to any of claims 4 to 6, wherein the refractive optical element is formed as part of the back surface of the contact lens.

9. The contact lens according to any of claims 4 to 7, wherein the refractive optical element is formed as parts of both the annular optical surface area and the back surface of the contact lens.

10. The contact lens according to any of claims 4 to 9, wherein the refractive optical element is an annular radial prism.

1 1. The contact lens according to claim 10, wherein the annular radial prism is arranged‘base out’ in the annular region, with an apex of the annular radial prism pointing towards the first optical axis.

12. The contact lens according to claim 10, wherein the annular radial prism is arranged‘base in’ in the annular region with an apex of the annular radial prism pointing away from the first optical axis.

13. The contact lens according to any previous claim, wherein the second

negative focal power is up to 5 dioptres less negative than the first negative focal power.

14. The contact lens according to any previous claim, wherein a diameter of the first optical surface area is at least 3.0 mm.

15. The contact lens according to any previous claim, wherein an outer

diameter of the annular optical surface area is at least 4.0 mm.

16. The contact lens according to any previous claim, wherein the annular

region comprises a second refractive optical element in series with the annular optical surface area and the first refractive optical element, the second refractive optical element being configured to translate the annular focal region relative to the first axis.

17. The contact lens according to any previous claim, wherein the body

comprises one or more additional annular regions concentrically surrounding the first annular region, each of the one or more additional annular regions having a corresponding additional annular optical surface area having a corresponding negative focal power, each of the

corresponding negative focal powers being less negative than the first negative focal power.

18. The contact lens according to claim 17, wherein each of the one or more additional annular regions comprises at least one refractive optical element in series with the corresponding additional annular optical surface area and cooperating with the corresponding additional annular optical surface area to form an additional annular focal region.

19. The contact lens according to any previous claim, wherein the contact lens is a disposable lens, in particular a daily disposable lens or a monthly disposable lens.

20. A method of treating or slowing the progression of myopia in a person, the method comprising:

applying to the eye or eyes of the person or prescribing for the person, a contact lens or lenses,

each contact lens having a body, the body comprising a central region and at least one annular region surrounding the central region, wherein the central region has a first optical surface area having a first negative focal power, the first optical surface area being configured to create a focused image on or near a retinal surface of the eye, to correct the myopia; the annular region has an annular optical surface area having a second negative focal power, the second negative focal power being less negative than the first negative focal power;

the annular region is configured to create an annular focal region located anterior to the retinal surface, thus creating an annular region of defocus on the retinal surface.

21.The method according to claim 20, wherein the annular region comprises a refractive optical element in series with the annular optical surface area and cooperating with the annular optical surface area to form the annular focal region.

22. The method according to any of claims 20 or 21 , wherein the first negative focal power and the second negative focal power ranges between 0.5 and 5.0 dioptres.