Contact lens for myopia with or without astigmatism

1 . A contact lens for a myopic eye, the contact lens comprising:

a front surface;

a back surface;

an optical center;

an optical axis;

an optical zone about the optical center, the optical zone comprising a power map characterised by a plurality of meridional power distributions across the optical zone, and a plurality of azimuthal power distributions about the optical axis; and

a non-optical peripheral carrier zone about the optical zone, the non-optical peripheral carrier zone comprising a plurality of azimuthal thickness distributions about the optical axis;

wherein at least one of the azimuthal power distributions is partially variant and is devoid of mirror symmetry; and wherein at least one of the meridional power distributions is partially variant and is devoid of mirror symmetry;

wherein the power map, at least in part, provides a foveal correction for the eye, and at least in part, provides a conoid of partial blur, serving as a directional cue, or an optical signal, at the retina of the myopic eye for at least one of slowing, retarding, or reducing myopia progression;

wherein the contact lens is configured to substantially freely rotate when on the eye under the influence of a blink action of an eyelid of the eye, including a configuration of the non-optical peripheral carrier zone comprising at least one of the azimuthal thickness distributions being substantially invariant to facilitate the substantially free rotation of the contact lens on the eye or comprising at least one rotation assisting feature; and

wherein due to the configuration of the non-optical peripheral carrier zone, the contact lens substantially freely rotates on the eye in different orientations of more than 180 degrees.

2 . The contact lens of the claim 1 , wherein only one of the pluralities of the meridional power distributions has mirror symmetry along the optical zone and none of the pluralities of the azimuthal power distributions has mirror symmetry about the optical axis.

3 . The contact lens of claim 1 , wherein the power map is at least 40% of the optical zone, and the remainder of the optical zone is configured substantially with a spherical correction for the myopic eye without astigmatism.

4 . The contact lens of claim 1 , wherein the power map is at least 40% of the optical zone, and the remainder of the optical zone is configured substantially with an astigmatic correction for the myopic eye with astigmatism.

5 . The contact lens of claim 1 , wherein the power map spans at least 3 mm of the central region of the optical zone.

6 . The contact lens of claim 1 , wherein the power map is achieved using the front surface, the back surface or both the front and back surfaces of the contact lens.

7 . The contact lens of claim 1 , wherein the at least one of the partially variant meridional power distributions is further configured to be radially variant.

8 . The contact lens of claim 7 , wherein the radial power variation in the at least one of the partially variant meridional power distributions is between 0 and −1D.

9 . The contact lens of claim 1 , wherein at least one of the partially variant meridional distributions includes a radial spoke with an invariant power distribution.

10 . The contact lens of claim 1 , wherein the difference between a maximum power and a minimum power within the meridionally varying power distributions across the optical zone, and the azimuthally varying power distributions about the optical axis, provides a delta power; wherein the delta power is at least +1.25 D.

11 . The contact lens of claim 1 , wherein the conoid of partial blur has a depth of at least 0.5 mm at the retina of the eye; wherein the conoid of partial blur spans at least a para-macular region of the retina of the eye; and wherein the para-macular region includes at least 20-degree field on the retina of the myopic eye.

12 . The contact lens of claim 1 , wherein the conoid of partial blur is irregular and not a regular conoid of Sturm; wherein the conoid of partial blur includes a sagittal plane and a tangential plane; wherein the tangential plane is located in front of the retina for at least one location within 20 degrees field of the retina of the eye; and wherein the sagittal plane is located substantially close to the retina of the eye, for at least one location within 20 degrees field of the retina of the eye.

13 . The contact lens of claim 1 , wherein the plurality of azimuthal thickness distributions are defined with a desired width spanning a range of arbitrary radial distances in the non-optical peripheral carrier zone, wherein the desired width is between 3.5 mm and 7.2 mm of the non-optical peripheral carrier zone.

14 . The contact lens of claim 1 , wherein the substantially free rotation is gauged as the rotation of the contact lens by 180 degrees at least thrice per 8 hours of lens wear, and at least 15 degrees within 1 hour of lens wear.

15 . The contact lens of claim 1 , wherein the configuration of the contact lens to substantially freely rotate when on the eye comprises the at least one rotation assisting feature which allows for a desired lens rotation providing a desired visual performance while maintaining the desired spatially and temporally varying optical stop signal for the myopic eye such that the efficacy of the directional signal remains substantially consistent over time.

16 . The contact lens of claim 1 , wherein the power map in conjunction with the substantially free rotation of the contact lens offers a temporally and spatially varying directional cue, or optical stop signal, for the myopic eye to substantially control eye growth of the myopic eye consistently over time.

17 . The contact lens of claim 1 , wherein the visual performance with the contact lens is substantially similar to that of a single vision contact lens for the myopic eye.

18 . The contact lens of claim 1 , wherein the at least one of the azimuthal power distributions is defined using a cosine distribution with reduced frequency, that is, half (½) of a normal frequency; wherein the normal frequency is defined with two cosine cycles over 360° or 2π radians.

19 . The contact lens of claim 1 , wherein the plurality of azimuthal thickness distributions are substantially invariant to facilitate the substantially free rotation of the contact lens.

20 . The contact lens of claim 19 , wherein the substantial invariance means a variation such that a peak-to-valley thickness is no more than 40 μm; wherein the peak-to-valley thickness is defined as a difference between a thickest point and a thinnest point within the plurality of azimuthal distributions of the non-optical peripheral carrier zone about the optical axis.

21 . The contact lens of claim 1 , wherein at least one azimuthal thickness distribution of the plurality of azimuthal thickness distributions is substantially variant to facilitate the substantially free rotation of the contact lens.

22 . The contact lens of claim 21 , wherein at least one of the azimuthal thickness distributions is configured with at least one rotation assisting; wherein the at least one rotation assisting feature is represented using a periodic function with a periodicity; wherein the periodic function is a saw-tooth profile, or a sinusoidal profile, or a sum of sinusoidal profiles, or a quasi-sinusoidal profile; and wherein the periodicity of the periodic function is no less than 6 defined over 0 to 2π radians, and the rate of thickness change is different for the increase than for the decrease; and wherein the maximum thickness variation within the at least one rotation assisting feature is between 10 μm to 40 μm.

23 . A contact lens for a myopic eye, the contact lens comprising:

a front surface;

a back surface;

an optical center;

an optical axis;

an optical zone about the optical center, the optical zone comprising a power map characterised by a plurality of meridional power distributions across the optical zone, and a plurality of azimuthal power distributions about the optical axis; and

a non-optical peripheral carrier zone about the optical zone, the non-optical peripheral carrier zone comprising a plurality of azimuthal thickness distributions about the optical axis;

wherein at least one of the azimuthal power distributions is partially variant and is devoid of mirror symmetry; and wherein at least one of the meridional power distributions is partially variant and is devoid of mirror symmetry;

wherein the power map, at least in part, provides a foveal correction for the eye, and at least in part, provides a conoid of partial blur, serving as a directional cue, or an optical signal, at the retina of the myopic eye for at least one of slowing, retarding, or reducing myopia progression;

wherein the non-optical peripheral carrier zone is configured to facilitate on-eye lens rotation, the configuration of the non-optical peripheral carrier zone comprising at least one of the azimuthal thickness distributions being substantially invariant to facilitate substantially free rotation of the contact lens on the eye or comprising at least one rotation assisting feature; and

wherein the conoid of partial blur has a depth of at least 0.5 mm at the retina of the eye; wherein the conoid of partial blur spans at least a para-macular region of the retina of the eye; and wherein the para-macular region includes at least 20-degree field on the retina of the myopic eye.

24 . A contact lens for a myopic eye, the contact lens comprising:

a front surface;

a back surface;

an optical center;

an optical axis;

an optical zone about the optical center, the optical zone comprising a power map characterised by a plurality of meridional power distributions across the optical zone, and a plurality of azimuthal power distributions about the optical axis; and

a non-optical peripheral carrier zone about the optical zone, the non-optical peripheral carrier zone comprising a plurality of azimuthal thickness distributions about the optical axis;

wherein at least one of the azimuthal power distributions is partially variant and is devoid of mirror symmetry; and wherein at least one of the meridional power distributions is partially variant and is devoid of mirror symmetry;

wherein the power map, at least in part, provides a foveal correction for the eye, and at least in part, provides a conoid of partial blur, serving as a directional cue, or an optical signal, at the retina of the myopic eye for at least one of slowing, retarding, or reducing myopia progression;

wherein the non-optical peripheral carrier zone is configured to facilitate on-eye lens rotation, the configuration of the non-optical peripheral carrier zone comprising at least one of the azimuthal thickness distributions being substantially invariant to facilitate substantially free rotation of the contact lens on the eye or comprising at least one rotation assisting feature; and

wherein at least one of the azimuthal thickness distributions is substantially invariant to facilitate substantially free rotation of the contact lens and wherein the substantially free rotation is gauged as a rotation of the contact lens by 180 degrees at least thrice per 8 hours of lens wear, and at least 15 degrees within 1 hour of lens wear.

25 . A contact lens for a myopic eye, the contact lens comprising:

a front surface;

a back surface;

an optical center;

an optical axis;

an optical zone about the optical center, the optical zone comprising a power map characterised by a plurality of meridional power distributions across the optical zone, and a plurality of azimuthal power distributions about the optical axis; and

a non-optical peripheral carrier zone about the optical zone, the non-optical peripheral carrier zone comprising a plurality of azimuthal thickness distributions about the optical axis;

wherein at least one of the azimuthal power distributions is partially variant and is devoid of mirror symmetry; and wherein at least one of the meridional power distributions is partially variant and is devoid of mirror symmetry;

wherein the power map, at least in part, provides a foveal correction for the eye, and at least in part, provides a conoid of partial blur, serving as a directional cue, or an optical signal, at the retina of the myopic eye for at least one of slowing, retarding, or reducing myopia progression;

wherein the non-optical peripheral carrier zone is configured to facilitate on-eye lens rotation, the configuration of the non-optical peripheral carrier zone comprising at least one of the azimuthal thickness distributions being substantially invariant to facilitate substantially free rotation of the contact lens on the eye or comprising at least one rotation assisting feature; and

wherein the at least one rotation assisting feature is selected to allow for a desired lens rotation providing a desired visual performance while maintaining the desired spatially and temporally varying optical stop signal for the myopic eye such that the efficacy of the directional signal remains substantially consistent over time.