Externally worn ophthalmic lens

Abstract

The present invention provides a continuously zoomable extracorneal wearable lens, which can form effective and controllable peripheral defocus while ensuring visual quality, prevent the growth of the eye axis, delay the development of myopia or provide optical correction for patients with myopia combined with presbyopia. The continuously zoomable extracorneal wearable ophthalmic lens of the present invention at least includes a central optical zone, a mid-peripheral optical zone, and a stable defocus zone that are sequentially distributed radially outward from the center. Among them, the average optical power change rate of the central optical zone is, the average optical power change rate of the mid-peripheral optical zone is, and the average optical power change rate of the stable defocus zone is. The three satisfy:

Description

Technical Field

[0001] The present invention relates to the field of ophthalmology, and in particular to an extraocular ophthalmic lens which utilizes a peripheral defocus mechanism to delay the progression of myopia. Background Art

[0002] Defocus (Defocus, out-of-focus) is the counterpart of focus. Defocus means that the image plane is not in focus. It is divided into two states: front defocus (before focus) and back defocus (after focus).

[0003] The main reason for the increase in myopia is the extension of the eye axis. Every 1.00mm extension increases the degree of myopia by 3.00 degrees. The latest medical research confirms that the extension of the eyeball depends on the retina (such as Figure 1 Peripheral defocus (shown as 100 in the figure) is called myopic defocus when the focus falls in front of the retina according to the concept of refraction (as shown in the figure). Figure 1 101), and those that fall behind the retina are called hyperopic defocus (such as Figure 1 The center of the retina of a myopic eye is myopic defocused, while the periphery of the retina is hyperopic defocused. This hyperopic defocus of the periphery of the retina is the main reason for the continuous increase in the degree of myopia.

[0004] The eyeball has the characteristic of relying on peripheral retinal imaging to induce eyeball development, especially for myopia in adolescents under 18 years old. If the peripheral retinal imaging is hyperopic defocus, the retina will tend to grow toward the image point, and the length of the eyeball will be extended. If the peripheral retinal imaging is myopic defocus, the eyeball will stop extending. If modern medical methods are used to correct peripheral retinal hyperopic defocus or artificially form peripheral retinal myopic defocus, the degree of myopia can be prevented from increasing. At the same time, the cause of peripheral retinal defocus can be identified, which can effectively prevent the occurrence and progression of myopia.

[0005] The concept of peripheral defocus was sorted out and summarized in the actual clinical practice of optometry. Initially, doctors found that the axial length and myopia growth rate of some orthokeratology lens wearers were delayed, and then discovered the role of peripheral defocus in this process, forming the theory of peripheral defocus to control myopia. At present, orthokeratology lenses (except for drugs) are considered to be the best optical intervention measures to delay the development of myopia.

[0006] Figure 2A This is a schematic diagram of the axial cross-section distribution of a corneal reshaping lens designed with four arc zones on the inner surface. Figure 2AAs shown in the figure, the base curve region 200 contacts the central region of the human cornea, with a relatively flat surface shape, which is used to flatten the corneal surface; the reverse curve region 201 has a relatively steep surface shape, which is used to stabilize the flattening effect of the base curve and ensure a certain amount of tear storage; the fitting curve region 202 is mainly used to stabilize the lens; the edge curve region 203 ensures the flow of tears between the cornea and the lens periphery. Under the combined action of the base curve and the reverse curve, the refractive power distribution of the cornea after shaping is as shown in Figure 2B . Among them, the refractive power change in the central cornea is flat, meeting the daily visual needs of the wearer, which is the myopia correction area; the refractive power change in the peripheral cornea is steep, making the visual focus fall in front of the retina, forming myopic peripheral defocus. The light rays of the human eye for seeing objects enter the eye through the pupil. Therefore, the myopic defocus in the entrance pupil area plays a major role in delaying the development of myopia; at the edge of the reverse curve, the refractive power change of the cornea gradually becomes flat again to maintain the maximum defocus amount within a certain range and form the "bull's-eye ring" in optometry (as shown by 204 in Figure 2C ). Under the changing trend of "flat - steep - flat" of the corneal refractive power, the myopic peripheral defocus mechanism of "myopia correction - defocus in the entrance pupil area - stable defocus of the 'bull's-eye ring'" is formed, which can effectively delay the development of myopia while correcting myopia.

[0007] The main disadvantages of corneal reshaping lenses are complex fitting, different shaping effects for different individuals, different maximum defocus amounts and defocus ranges for patients with different eye characteristics, and there is also a daytime regression phenomenon. The fitting of non-plastic peripheral defocus contact lenses is simple, and the maximum defocus amount and defocus range depend on the optical design of the lens, and a stable defocus effect can be formed after wearing. In the prior art, the optical designs of non-plastic contact lenses that use the peripheral defocus mechanism to delay the development of myopia mainly include the alternating concentric circle design and the progressive multifocal design.

[0008] The alternating concentric circle design divides the lens surface structure into multiple regions, and two curvature radii are alternately distributed in each region. This design of lens will form two clear focal points, and there is interference between the two focal points, forming a halo phenomenon. The lens of the progressive multifocal design mainly includes a central myopia correction area and a peripheral defocus area. The change in the optical power of the myopia correction area is small (it can be approximately considered that the optical power is constant), and the optical power of the peripheral defocus area continuously increases from the center to the periphery. Some lenses of this design have an infinite increase in the optical power at the edge of the lens optical zone, and some lenses start to decrease after the optical power reaches the maximum value, and cannot provide a stable maximum defocus amount, and the defocus effect is unstable.

[0009] The common drawbacks of the above two designs are mainly that the curvature radii of each region are different, and a large amount of stray light will be caused at the junction between the two regions, resulting in poor imaging quality. In addition, at present, the defocus areas of contact lenses used to slow down the development of myopia are all outside the common optical region (pupil region), and less myopic peripheral defocus is formed in the entrance pupil region, resulting in the ineffectiveness of the defocus area and insignificant myopia control effect. There is literature indicating that patients with a larger pupil diameter can better inhibit the growth of the eye axis after wearing orthokeratology lenses, and there is a certain correlation between the pupil diameter and the myopia control effect, which also indirectly confirms that more defocus light falling in front of the retina in the pupil region will have a better effect on slowing down the development of myopia.

[0010] Therefore, there is a particular need for an extraocular wearable lens with high imaging quality, which can induce the formation of peripheral defocus in the entrance pupil region and has a stable and controllable maximum defocus amount to solve the existing problems mentioned above. Summary of the Invention

[0011] In view of this, the object of the present invention is to provide an extraocular wearable lens that can form effective and controllable peripheral defocus while ensuring visual quality, prevent the growth of the eye axis, and slow down the development of myopia.

[0012] To achieve the above object, the present invention provides an extraocular wearable ophthalmic lens, including a lens, characterized in that the lens at least includes a central optical region, a mid-peripheral optical region, and a stable defocus region that are sequentially distributed radially outward from the center, wherein the average optical power change rate of the central optical region is The average optical power change rate of the mid-peripheral optical region is The average optical power change rate of the stable defocus region is

[0013] By using the extraocular wearable ophthalmic lens of the present invention, since the average optical power change rates of the central optical region, the mid-peripheral optical region, and the stable defocus region satisfy The optical power change trends of the central optical region, the mid-peripheral optical region, and the stable defocus region are "flat - steep - flat". In view of the deficiencies of the prior art, the lens can induce the formation of peripheral defocus in the entrance pupil region, provide a stable and controllable maximum defocus amount, avoid stray light at the junction, form effective and controllable peripheral defocus while ensuring visual quality, prevent the growth of the eye axis, and slow down the development of myopia. The lens of the present invention can not only correct myopia, prevent the growth of the eye axis, and effectively slow down the development of myopia, but also correct presbyopia and provide near vision and far vision for presbyopic patients at the same time.

[0014] Furthermore, the diameter of the central optical region is ≤4.0 mm, preferably ≤3.0 mm, and more preferably ≤2.6 mm.

[0015] Further, the change in the optical power of the central optical zone ΔD1 ≤ 1.0 D, preferably ΔD1 ≤ 0.5 D. Thus, the average optical power change rate of the central optical zone is small (relative to the overall optical power change trend of the lens), and the optical power change is flat to provide stable central vision.

[0016] Further, the width of the middle peripheral optical zone is 0 - 4.0 mm, preferably 1.0 - 3.0 mm, more preferably 1.5 - 1.7 mm.

[0017] Further, the change in the optical power of the middle peripheral optical zone ΔD2 ≥ 0.5 D, preferably ΔD2 ≥ 2.0 D, more preferably ΔD2 ≥ 4.0 D. Thus, the average optical power change rate of the middle peripheral optical zone is large (relative to the overall optical power change trend of the lens), and the optical power change is steep to provide sufficient peripheral defocus amount in the entrance pupil area.

[0018] Further, the optical power of the middle peripheral optical zone continuously increases as the aperture increases, that is, at any aperture m, k m > 0 (m > 0).

[0019] Further, the width of the stable defocus zone is 0 - 3.0 mm, preferably 0.5 - 1.0 mm.

[0020] More preferably, the change in the optical power of the stable defocus zone ΔD3 ≤ 0.5 D. Thus, the optical power change of the stable defocus zone (relative to the whole lens) is flat to maintain the maximum defocus amount unchanged at a certain aperture.

[0021] Optionally further, the change in the optical power of the stable defocus zone of the lens ΔD3 ≥ 0.5 D. Thus, the optical power change (relative to the whole lens) is not flat to further increase the peripheral defocus amount.

[0022] Further, the optical power changes of the central optical zone, the middle peripheral optical zone, and the stable defocus zone are continuous. Thus, the optical powers of the central optical zone, the middle peripheral optical zone, and the stable defocus zone change continuously, which can avoid stray light and image jumping at the joints, and form effective and controllable peripheral defocus while ensuring visual quality.

[0023] More preferably, the front surfaces of the central optical zone, the middle peripheral optical zone, and the stable defocus zone are formed by aspheres, and the expression of the aspheric curve of the front surface in the YZ plane is:

[0024]

[0025] Among them, c is the reciprocal of the curvature radius of the surface of the basic spherical surface of the optical part, y is the vertical distance from any point on the aspherical curve to the horizontal coordinate axis (Z), Q is the aspherical coefficient, A 2i is the high-order aspherical coefficient, and the aspherical surface is obtained by rotationally symmetrically varying the aspherical curve around the horizontal coordinate axis (Z). In this way, the optical powers of the central optical zone, the mid-peripheral optical zone, and the stable defocus zone continuously change, which can avoid stray light and image jump phenomena at the joints. While ensuring visual quality, effective and controllable peripheral defocus is formed.

[0026] Further more preferably, the front surfaces of the central optical zone and the mid-peripheral optical zone are composed of a section of aspherical surface with the same curvature radius. In this way, there is no obvious boundary between the two zones, the optical power changes smoothly at any aperture, the optical power change rate shows a gradual change trend, avoiding stray light phenomena at the joints, and reducing visual discomforts such as subjective dizziness and headache of patients.

[0027] Further optionally, the central optical zone, the mid-peripheral optical zone, and the stable defocus zone are composed of multiple sections of spherical surfaces and / or aspherical surfaces. In this way, the flexibility of lens processing design can be improved, while reducing the design difficulty of the lens, and it is easier to achieve the optical power change trend of "flat - steep - flat" for the central optical zone, the mid-peripheral optical zone, and the stable defocus zone.

[0028] Further, the optical power of the lens is +25D to -25.0D. By using the extracorneal-wearing ophthalmic lens of the present invention, the lens can not only correct myopia, prevent the growth of the eye axis, and effectively delay the development of myopia, but also correct presbyopia, and provide near vision and far vision for presbyopic patients at the same time.

[0029] Further, the diameter of the lens is 7.0 to 25.0 mm, preferably 9.0 to 16.0 mm.

[0030] Further, the lens is made of a soft or hard material, and the refractive index of the material is 1.00 to 1.60, preferably 1.40 to 1.50.

[0031] Further, the material of the lens is a high-oxygen-permeable material, and the DK value (oxygen permeability coefficient) of the material is (0 - 300)×10 -11 (cm 2 / s)[(mlO2×mmHg)], preferably (80 - 260)×10 -11 (cm 2 / s)[(mlO2×mmHg)].

[0032] Further, the lens is a corneal or scleral contact lens. Preferably, the lens is a soft contact lens or / and a rigid gas-permeable contact lens.

[0033] Further, it also includes a peripheral zone located radially outside the stable defocus zone. In the lens of the present invention, the area outside the stable defocus zone within the total diameter of the lens is the peripheral zone, which plays a positioning role and is mainly determined by the morphology of the human corneal, without optical effect.

[0034] Further preferably, the central optical zone, the mid-peripheral optical zone, the stable defocus zone and the peripheral zone are concentric circular ring structures.

[0035] For the continuous zoom extracorneal wearable lens of the present invention, the optical design of the lens refers to the refractive power distribution of the cornea after orthokeratology. Compared with the prior art, peripheral defocus is formed within a range of less than 3.0 mm in aperture, so that the light entering the pupil area falls in front of the retina (the diameter of the human eye pupil is generally 2.5 - 5 mm, with an average of 4.0 mm), effectively delaying the development of myopia; the optical power of the stable defocus zone preferably changes flatly, providing a stable and controllable maximum defocus amount; the central optical zone and the mid-peripheral optical zone are preferably designed as an arc section, which can reduce the phenomenon of stray light and improve visual quality.

[0036] Term definition:

[0037] The term "radial" used in the present invention refers to the straight-line direction along the radius or diameter from the center of the lens.

[0038] The term "aperture" used in the present invention refers to the diameter size of the lens surface in the radial direction.

[0039] The term "ring width" used in the present invention refers to the width of a certain circular ring area in the radial direction. For example, for a certain circular ring area of the lens, its ring width refers to the length of the straight line along the radius direction from the center of the lens within this area.

[0040] The terms indicating the azimuth relationship used in the present invention, such as "front" and "back", are in terms of the distance from the surface of the eye cornea. For example, for the lens of the present invention, the "back surface" is the surface closer to the eye cornea than the "front surface".

[0041] The term "optical power variation amount ΔD m " refers to the difference between the maximum optical power and the minimum optical power within the indicated aperture range.

[0042] The term "optical power change rate k m " refers to the optical power change rate at any aperture m, that is

[0043]

[0044] where D m represents the optical power of the lens at aperture m.

[0045] The term "average rate of change of optical power" used in the present invention refers to the average value of the absolute value |k m | of the rate of change of optical power k at each point within the specified aperture range. m

[0046] The terms "flat" and "steep" used in the present invention are relative. For example, the trend of the change in optical power in the central optical zone, the middle peripheral optical zone, and the stable defocus zone is "flat - steep - flat", which is the trend change in comparison among the three; in addition, if only "the change in optical power is flat" is described, it means that the average rate of change of optical power in the specified range is relatively small compared to the overall trend of the change in optical power of the entire lens, and "the change in optical power is steep" means that the average rate of change of optical power in the specified range is relatively large compared to the overall trend of the change in optical power of the entire lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic diagram of the retina, myopic defocus, and hyperopic defocus;

[0048] Figure 2A is a schematic diagram of the cross-sectional structure distribution of an orthokeratology lens;

[0049] Figure 2B is a diagram of the corneal refractive power distribution after orthokeratology lens shaping;

[0050] Figure 2C is a corneal topographic map after orthokeratology lens shaping;

[0051] Figure 3A is a schematic diagram of the cross-sectional structure distribution of the lens in the specific embodiment of the present invention;

[0052] Figure 3B is a schematic diagram of the radius of curvature of each area of the lens in the specific embodiment of the present invention;

[0053] Figure 3C is a schematic diagram of the optical power distribution of the cross-section of the lens in the specific embodiment of the present invention;

[0054] Figure 3D is the corneal topographic map after wearing the lens of Embodiment 1 of the present invention;

[0055] Figure 4 is a schematic diagram of the optical power distribution of the cross-section of the lens of Embodiment 2 of the present invention;

[0056] Figure 5 is a schematic diagram of the optical power distribution of the cross-section of the lens of Embodiment 3 of the present invention;

[0057] Figure 6A is a schematic diagram of the optical power distribution of the cross-section of the lens of Embodiment 4 of the present invention;

[0058] Figure 6B This is a schematic diagram of the dioptric power distribution of the lens axial section in Embodiment 5 of the present invention.

[0059] Figure 6C This is a schematic diagram of the dioptric power distribution of the lens axial section in Embodiment 6 of the present invention

[0060] Explanation of reference numerals

[0061] 100 Retina; 101 Myopic peripheral defocus imaging defocus area; 102 Hyperopic peripheral defocus imaging defocus area; 200 Base curve area of corneal reshaping lens; 201 Reverse curve area of corneal reshaping lens; 202 Fitting curve area of corneal reshaping lens; 203 Edge curve of corneal reshaping lens; 204 "Bull's eye ring" formed after corneal reshaping lens shaping; 300 Central optical zone of the lens in the specific embodiment; 301 Mid-peripheral optical zone of the lens in the specific embodiment; 302 Stable defocus zone of the lens in the specific embodiment; 303 Peripheral zone of the lens in the specific embodiment; R1 Front surface curvature radius of the central optical zone and mid-peripheral optical zone in Embodiment 1 of the present invention; R2 Front surface curvature radius of the stable defocus zone in Embodiment 1 of the present invention. Specific embodiment

[0062] The specific embodiment of the present invention provides an ophthalmic lens for extraocular wear with continuous zoom, which includes a lens. The lens has front and back surfaces. The back surface faces the cornea during wearing, contacts the cornea or sclera, and plays a positioning role, and is composed of an aspherical surface, a spherical surface or multiple arcs; the front surface plays an optical role. The lens includes a central optical zone, a mid-peripheral optical zone, a stable defocus zone and a peripheral zone that are sequentially distributed radially outward from the center. These multiple zones are preferably designed in a concentric circular ring shape. In the embodiment of the present invention, outside the stable defocus zone within the total diameter range is the peripheral zone, and the peripheral zone plays a positioning role, which is mainly determined by the shape of the human cornea and has no optical effect. The gist of the present invention is that the average dioptric power change rate of the central optical zone is The average dioptric power change rate of the mid-peripheral optical zone is The average dioptric power change rate of the stable defocus zone is The three satisfy: In this way, the dioptric power change trends of the central optical zone, the mid-peripheral optical zone and the stable defocus zone are "flat - steep - flat".

[0063] Furthermore, the dioptric power of the lens can be +25D to -25.0D. The diameter of the lens can be 7.0 to 25.0 mm, preferably 9.0 to 16.0 mm. The diameter of the central optical zone can be ≤4.0 mm, preferably ≤3.0 mm, more preferably ≤2.6 mm.

[0064] Further, the change in dioptric power ΔD1 of the central optical zone can be ≤ 1.0 D, preferably ΔD1 ≤ 0.5 D, and the change in dioptric power of the central optical zone is flat to provide stable central vision.

[0065] Further, the ring width of the mid-peripheral optical zone can be 0 - 4.0 mm, preferably 1.0 - 3.0 mm, and more preferably 1.5 - 1.7 mm.

[0066] Further, the change in dioptric power ΔD2 of the mid-peripheral optical zone can be ≥ 0.5 D, preferably ΔD2 ≥ 2.0 D, and more preferably ΔD2 ≥ 4.0 D. The change in dioptric power of the mid-peripheral optical zone is steep to provide sufficient peripheral defocus in the entrance pupil area.

[0067] Further, the dioptric power of the mid-peripheral optical zone continuously increases as the aperture increases. At any aperture m, k m > 0 (m > 0).

[0068] Further, the ring width of the stable defocus zone can be 0 - 3.0 mm, preferably 0.5 - 1.0 mm.

[0069] More preferably, the change in dioptric power ΔD3 of the stable defocus zone ≤ 0.5 D, and the change in dioptric power is flat to maintain the maximum defocus amount constant at a certain aperture.

[0070] Further optionally, the change in dioptric power ΔD3 of the stable defocus zone ≥ 0.5 D, and the change in dioptric power is not flat.

[0071] Further, the change in dioptric power of the central optical zone, mid-peripheral optical zone, and stable defocus zone is continuous.

[0072] More preferably, the central optical zone, mid-peripheral optical zone, and stable defocus zone are formed by aspheres. The expression of the aspheric curve on the front surface in the YZ plane is:

[0073]

[0074] where c is the reciprocal of the surface curvature radius of the basic spherical surface of the optical part, y is the perpendicular distance from any point on the aspheric curve to the horizontal coordinate axis (Z), Q is the aspheric coefficient, A 2i is the high-order aspheric coefficient, and the aspheric surface is obtained by rotationally symmetrically changing the aspheric curve around the horizontal coordinate axis (Z).

[0075] More preferably, the front surfaces of the central optical zone and mid-peripheral optical zone are composed of a section of aspheric surface and have the same curvature radius, so there is no obvious boundary between the two zones, avoiding stray light phenomena at the junction.

[0076] Optionally, the central optical zone, the middle peripheral optical zone, and the stable defocus zone are composed of multiple segments of spherical surfaces and / or aspherical surfaces. Through a variety of combinations of curvature radii, the change trend of the optical power of the central optical zone, the middle peripheral optical zone, and the stable defocus zone is "flat - steep - flat".

[0077] Furthermore, the lens can be made of a soft or hard material, and the refractive index of the material is 1.00 - 1.60, preferably 1.40 - 1.50.

[0078] Preferably, the material of the lens is a high - oxygen - permeability material, and the DK value (oxygen permeability coefficient) of the material is (0 - 300)×10 -11 (cm 2 / s)[(mlO2×mmHg)], preferably (80 - 260)×10 -11 (cm 2 / s)[(mlO2×mmHg)].

[0079] By using the above - mentioned lens, its optical design refers to the corneal refractive power distribution after orthokeratology. Aiming at the deficiencies of the prior art, the lens can induce the formation of peripheral defocus in the entrance pupil area, provide a stable and controllable maximum defocus amount, avoid stray light at the junction, and while ensuring visual quality, form an effective and controllable peripheral defocus to prevent the growth of the eye axis and delay the development of myopia.

[0080] For the extracorneal wearable lens of the present invention, the optical design of the lens refers to the corneal refractive power distribution after orthokeratology. Compared with the prior art, peripheral defocus is formed within a range of less than 3.0 mm in aperture, so that the light entering the pupil area falls in front of the retina (the diameter of the human eye pupil is generally 2.5 - 5 mm, with an average of 4.0 mm), effectively delaying the development of myopia; the optical power of the stable defocus zone preferably changes flatly to provide a stable and controllable maximum defocus amount; in addition, the central optical zone and the middle peripheral optical zone are preferably designed as a single arc, which can reduce the phenomenon of stray light and improve visual quality.

[0081] In addition, for the extracorneal wearable lens of the present invention, the lens can not only correct myopia, prevent the growth of the eye axis, and effectively delay the development of myopia, but also correct presbyopia and provide near - vision and far - vision for presbyopic patients at the same time.

[0082] It should be particularly noted that the lens design of the extracorneal wearable lens described in the present invention is preferably applied to many different contact lenses, and the contact lenses include but are not limited to corneal or scleral contact lenses. In addition, although the present invention is described with respect to contact lenses, it should be particularly noted that the lens design concept of the present invention can also be used for frame glasses, intraocular lenses, etc.

[0083] Next, some specific embodiments of the present invention are introduced.

[0084] Such as Figure 3A, the extracorneal wearing lens is a rigid gas-permeable contact lens (RGP), the posterior surface is spherical, the total diameter is 10.6 mm, and the posterior surface curvature radius Rp = 8.5 mm. The total diameter of the central optical zone (300) and the mid-peripheral optical zone (301) is 6.0 mm, the ring width of the stable defocus zone (302) is 1.0 mm, and the ring width of the peripheral zone (303) is 1.3 mm. As Figure 3B shown, the anterior surface curvature radius R1 of the central optical zone and the mid-peripheral optical zone is 9.478 mm, the anterior surface curvature radius R2 of the stable defocus zone is 8.5914 mm. At a 6.00 mm aperture in the segmented area, the stray light phenomenon in the entrance pupil area is reduced, and the visual quality is improved. As Figure 3C , it is a schematic diagram of the dioptric power distribution of the axial section of the contact lens. The dioptric power of the central optical zone is about -5.0 D, the total diameter is about 2.6 mm, the average dioptric power change rate is about 0.28 D / mm, and the dioptric power change is flat, which is used for myopia correction of patients with 500 degrees of myopia; the ring width of the mid-peripheral optical zone is about 1.7 mm, the dioptric power increases from -5.0 D to 0.05 D, and the average dioptric power change rate is 2.80 D / mm, and the dioptric power change is steep, which is used to form peripheral defocus and delay the development of myopia in patients; the dioptric power of the stable defocus zone is 0.4 ± 0.25 D, and the average dioptric power change rate is 0.33 D / mm, and the dioptric power change is flat, which is used to provide a stable and controllable maximum defocus amount. The dioptric power changes of the central optical zone, the mid-peripheral optical zone, and the stable defocus zone ( Figure 3C ) are consistent with the corneal refractive power distribution after orthokeratology ( Figure 2B ). The corneal topographic map and the dioptric power change trend after wearing the lens are as shown in Figure 3D , the lens provides about +5.5 D of myopic peripheral defocus, the defocus amount covered in the pupil area is sufficient, and there is an obvious "bull's-eye ring", which is consistent with the corneal topographic map ( Figure 3D ) distribution after orthokeratology; the vision is clear after wearing the lens, the imaging quality is relatively high, there are no obvious halos, headaches, etc. during daytime wearing, and the subjective visual quality is relatively good. The lens is Example 1, and its surface shape distribution is shown in Table 1.

[0085] Table 1 Example 1 of the extracorneal wearing lens of the present invention

[0086]

[0087] As shown in Table 2, it is the surface shape distribution of Example 2 of the extracorneal wearing lens of the present invention, and its axial section dioptric power change curve is as shown in Figure 4, this embodiment is particularly suitable for vision correction of patients with myopia combined with presbyopia. Embodiment 2 is a soft contact lens with a total diameter of 14.2 mm. The posterior surface is designed as a spherical surface with a radius of curvature Rp = 8.5 mm. The optical power of the central optical zone of Embodiment 2 is about -10.0 D, which meets the far vision requirements of patients with 1000-degree myopia; the optical power of the stable defocus zone is about -8.00 D, which meets the near vision requirements of patients with 1000-degree myopia and 200-degree presbyopia; the mid-peripheral optical zone is a transitional connection section between the central optical zone and the stable defocus zone, and the average optical power change rate is 1.44 D / mm. The optical power changes steeply, which can avoid phenomena such as image jump and stray light while meeting the near and far vision requirements of patients, and reduce symptoms such as subjective dizziness of patients.

[0088]

[0089] Table 2 Embodiment 2 of the extracorporeal wearing lens of the present invention

[0090] The implementation method of the present invention is mainly an aspherical design. Table 3 shows the specific parameters of the aspherical design of Embodiment 3 of the present invention. The front surfaces of the central optical zone, the mid-peripheral optical zone, and the stable defocus zone are 8th-order aspherical surfaces. The aspherical curve of the front surface in the YZ plane is obtained from Formula ①.

[0091]

[0092] The aspherical curve of the posterior surface in the YZ plane is obtained from Formula ②.

[0093]

[0094] In actual operation, each parameter is adjusted according to requirements to achieve the corresponding optical power change curve.

[0095] Figure 5 This is the axial section optical power change curve and the distribution of each zone of Optional Embodiment 3 of the present invention, and its surface type parameters are shown in Table 4.

[0096] Table 3 Surface type design parameters of Embodiment 3 of the extracorporeal wearing lens of the present invention

[0097]

[0098]

[0099] Table 4 Embodiment 3 of the extracorporeal wearing lens of the present invention

[0100] Figures 6A - 6C This is the axial section optical power change curve and the distribution of each zone of Optional Embodiments 4-6 of the present invention, and its surface type distribution is shown in Table 5. The posterior surface of each embodiment is designed as a spherical surface with a radius of curvature Rp = 8.5 mm.

[0101] Table 5 Examples 4 - 6 of the extraocular wearing lens of the present invention

[0102]

[0103] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above - mentioned embodiments, and what is described in the above - mentioned embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. An extraocularly worn ophthalmic lens, which comprises a lens, characterized in that, The lens at least includes a central optical zone, a mid-peripheral optical zone, and a stable defocus zone that are sequentially distributed radially outward from the center. Among them, the optical power of the central optical zone varies radially, and its average optical power change rate is The optical power of the mid-peripheral optical zone varies radially, and its average optical power change rate is The optical power of the stable defocus zone varies radially, and its average optical power change rate is 2. The extraocularly worn ophthalmic lens according to claim 1, wherein The diameter of the central optical zone is ≤4.0 mm, ≤3.0 mm, ≤2.6 mm or ≤2 mm.

3. The extracorporeal ophthalmic lens according to claim 1, wherein, The change in the optical power of the central optical zone, ΔD1, is ≤1.0 D or ΔD1 ≤0.5 D.

4. The extraocularly worn ophthalmic lens according to claim 1, wherein, The width of the intermediate peripheral optical zone is 0 - 4.0 mm, 1.0 - 3.0 mm or 1.5 - 1.7 mm.

5. The extraocularly worn ophthalmic lens according to claim 1, wherein, The change in the optical power of the intermediate peripheral optical zone, ΔD2, is ≥0.5 D, ΔD2 ≥2.0 D or ΔD2 ≥4.0 D.

6. The extraocularly worn ophthalmic lens according to claim 3, wherein, The change in the optical power of the intermediate peripheral optical zone, ΔD2, is ≥0.5 D, ΔD2 ≥2.0 D or ΔD2 ≥4.0 D.

7. The extraocularly worn ophthalmic lens according to claim 1, wherein, The optical powers of the central optical zone, the intermediate peripheral optical zone and the stable defocus zone continuously increase with the increase of the aperture.

8. The extraocularly worn ophthalmic lens according to claim 1, wherein, The width of the stable defocus zone is 0 - 3.0 mm or 0.5 - 1.0 mm.

9. The extraocularly worn ophthalmic lens according to claim 1 or 8, wherein, The change in the optical power of the stable defocus zone, ΔD3, is ≤0.5 D.

10. The extraocularly worn ophthalmic lens according to claim 1 or 8, characterized in that, The change in the optical power of the stable defocus zone, ΔD3, is ≥0.5 D.

11. The extraocularly worn ophthalmic lens according to claim 1, wherein, The changes in the optical powers of the central optical zone, the intermediate peripheral optical zone and the stable defocus zone are continuous.

12. The extraocularly worn ophthalmic lens according to claim 1, wherein, The front surfaces of the central optical zone, the intermediate peripheral optical zone and the stable defocus zone are formed by aspherical surfaces. The expression of the aspherical curve of the front surface in the YZ plane is: Wherein, c is the reciprocal of the curvature radius of the surface of the basic spherical surface of the optical part, y is the vertical distance from any point on the aspherical curve to the horizontal coordinate axis (Z), Q is the aspherical coefficient, A 2i is the high-order coefficient of the aspherical surface, and the aspherical surface is obtained by rotationally symmetrically varying the aspherical curve around the horizontal coordinate axis (Z).

13. The extraocularly worn ophthalmic lens according to claim 12, wherein, The said A 2i is not zero.

14. The extraocularly worn ophthalmic lens according to claim 12, wherein, The front surfaces of the central optical zone and the intermediate peripheral optical zone as a whole are composed of a section of aspherical surface with the same basic spherical curvature radius.

15. The extraocularly worn ophthalmic lens according to claim 12, wherein, The optical power of the central optical zone is less than that of the stable defocus zone.

16. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The average rate of change of the optical power of the central optical zone is 0.011 to 0.38 D / mm, 0.12 to 0.38 D / mm, 0.12 to 0.28 D / mm, or 0.12 to 0.24 D / mm.

17. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The average optical power change rate of the intermediate peripheral optical zone is 1.12 to 2.80 D / mm, 1.12 to 2.51 D / mm, 1.44 to 2.51 D / mm, or 1.82 to 2.51 D / mm.

18. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The average optical power change rate of the stable defocus region is 0.021 to 1.56 D / mm, 0.28 to 1.56 D / mm, 0.33 to 1.56 D / mm, or 0.33 to 0.92 D / mm.

19. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The average optical power change rate of the central optical zone is less than the average optical power change rate of the stable defocus zone 20. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The central optical zone, the intermediate peripheral optical zone and the stable defocus zone are composed of multiple sections of spherical and / or aspherical surfaces.

21. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The optical power of the lens is +25 D to -25.0 D.

22. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The diameter of the lens is 7.0 - 25.0 mm, or 9.0 - 16.0 mm.

23. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The lens is made of a soft or hard material. The refractive index of the material is 1.00 - 1.60, or 1.40 - 1.

50.

24. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The material of the lens is a high oxygen permeability material, and the oxygen permeability coefficient of the material, i.e., the DK value, is (0 to 300)×10 -11 (cm 2 / s)[(mlO2×mmHg)], or (80 to 260)×10 -11 (cm 2 / s)[(mlO2×mmHg)].

25. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The lens is a corneal or scleral contact lens.

26. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, The lens is a soft contact lens or / and a rigid gas permeable corneal contact lens.

27. The extraocularly worn ophthalmic lens according to any one of claims 1-8, characterized in that, It further includes a peripheral zone located radially outside the stable defocus zone.

28. The extraocularly worn ophthalmic lens according to claim 27, wherein, The central optical zone, the intermediate peripheral optical zone, the stable defocus zone and the peripheral zone are in a concentric circular ring structure.

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