Myopia prevention and control spectacle lens having fractal microstructure

Abstract

The present invention relates to the technical field of design and processing of optical lenses, and provides a myopia prevention and control spectacle lens having a fractal microstructure. The spectacle lens comprises a lens base; an optical area and a control area are provided on the lens base; the optical area comprises a central optical area, and the central optical area is an area having the center position of the spectacle lens as a center and a radius of R1; the control area surrounds the central optical area, and the control area is provided with a microstructure constructed by a fractal curve or fractal pattern on the plane of the lens base, or a microstructure constructed by a fractal curve or fractal pattern between layers of the lens base. According to the present invention, the degree of optical disturbance is increased by increasing the complexity of the peripheral microstructure as much as possible, thereby interfering with the process of myopia progression.

Description

Myopia prevention and control glasses with fractal microstructure

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 31, 2023, with application number CN2023109524092 and invention name “Myopia prevention and control eyeglass lenses with fractal microstructure”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention belongs to the technical field of design and processing of optical lenses, and in particular relates to myopia prevention and control spectacle lenses with fractal microstructures. Background Art

[0003] According to data from the National Health Commission, 600 million people in my country suffer from myopia. In 2020, the overall myopia rate among Chinese adolescents was 52.7%, including 14.3% for six-year-olds, 35.6% for primary school students, 71.1% for junior high school students, and 80.5% for high school students. The task of preventing and controlling myopia is arduous and urgent.

[0004] The current mainstream optical theory for myopia prevention and control is the optical defocus theory. This theory posits that if the image is focused in front of the retina (positive defocus), the eye axis is less likely to grow, and myopia is controlled; applying an image focused behind the retina (negative defocus) has the opposite effect. Current mainstream optical methods for myopia prevention and control include defocused frame glasses (hereinafter referred to as defocused glasses), orthokeratology (hereinafter referred to as OK glasses), and defocused soft corneal contact lenses (hereinafter referred to as defocused soft lenses). Within the existing theoretical framework, all three are believed to slow the progression of myopia by causing myopic defocus in the peripheral field of view.

[0005] In addition, there is another type of lens on the market that reduces the contrast of the peripheral vision. This myopia control theory believes that high-contrast signals are detrimental to myopia prevention and control. Therefore, reducing the contrast of the peripheral vision can help myopia control.

[0006] However, the theory of optical positive defocus cannot explain all clinical phenomena. In clinical practice, some adolescent myopic patients cannot effectively control their myopia even when given sufficient positive defocus optical signals, and their myopia may even rapidly worsen. Some patients' myopia is actually controlled after switching from OK lenses to peripheral defocus lenses. These clinical phenomena suggest that the theory of optical defocus is extremely incomplete, and that optical correction methods for myopia prevention and control require the support of a higher-level myopia control theory.

[0007] Currently, there are many products on the market based on the theory of optical positive defocus. Different from the theory of optical defocus, there is another type of lens on the market based on the theory of peripheral contrast.

[0008] 1) New Lexue Lenses: New Lexue lenses utilize a "Multi-Zone Positive Defocus" design (DIMS technology). 396 microlenses are arranged in an equilateral triangle grid within a ring-shaped area with an inner diameter of 9.4 mm and an outer diameter of approximately 33 mm at the optical center of the lens. Each microlens produces a myopic defocus of 3.5 D. The size and spacing of the microlenses are adjusted to maintain a stable ratio of defocus area to corrective area (targeting 50:50). This ensures a long-lasting myopic defocus effect for the wearer, resulting in better myopia control. In 2018, the Hong Kong Polytechnic University published a study titled "Multi-Zone Positive Defocus (DIMS) Spectacle Lenses for Delaying Myopia Progression: A Two-Year Randomized Controlled Clinical Study" in the British Journal of Ophthalmology. The study demonstrated that, with a larger sample size than similar studies and without additional screening criteria, the lenses effectively slowed myopia progression by 59% and axial length growth by 60%.

[0009] 2) Star Control Lenses: Star Control lenses are made with HALT high aspheric microlens technology brought by Essilor's R&D team. Designed with this technology, the Star Control lenses have 1021 microlenses that are invisible and distributed on 11 rings, all of which are positive defocus microlenses. The optical center spacing of the microlenses in adjacent rings of the Star Control lens is 2.41mm. Even when our eyes look peripherally, such as looking downward when looking at close objects, we can still obtain clear retinal macular central vision from the single-vision lens area within this gap. A three-year clinical trial involving 167 myopic children was conducted on this product. The results of the first year of the experiment showed that the average level of myopia progression in children wearing Star Control lenses was reduced by more than 60% compared with children wearing single-vision lenses (One-year myopia control efficacy of spectacle lenses with aspherical lenslets. Br J Ophthalmol 2022 Aug;106(8):1171-1176).

[0010] 3) Aura lenses: Different areas of the retina may respond differently to myopic defocus signals. Animal experiments have shown that defocus within the 10°-20° range around the fovea can produce the strongest myopia control effect. Aura lenses should be used as much as possible to strengthen intervention in the areas of the retina that are most sensitive to myopic defocus. Defocus lenses of different densities and sizes are rationally designed with light addition. Through a radial array arrangement, they apply stronger optical defocus to the most sensitive area of ​​myopic defocus within the 10°-20° range around the fovea, thereby strengthening myopia management effects and balancing the pursuit of excellent visual quality with improved patient compliance.

[0011] 4) Control Advantage lenses (Nikon): A genetic mutation that causes myopia causes myopic patients to express cone photoreceptors that are extremely insensitive to light. In myopic patients, the mutant cones consistently produce a small signal relative to their normal neighboring cones, resulting in a high contrast ratio between normal and mutant cones. This abnormally high retinal contrast signal can contribute to the progression of myopia. Control Advantage lenses utilize a different control mechanism than optical defocusing. They utilize Diffusion Optics Technology (DOT). DOT lenses contain light-scattering centers that scatter light as it passes through the lens, resulting in a low signal difference between adjacent cones while maintaining excellent visual acuity and functional peripheral vision. Researchers used these lenses in the CYPRESS (Efficacy and Safety Study), a 36-month randomized controlled trial. Results from the 24th month are now available, and 89% of children are continuing to wear them for the final 12 months. Data from the first two years showed that if worn full-time, the progression of myopia over two years was reduced by 59% and the axial length growth was reduced by 38% (Control of myopia using diffusion optics spectacle lenses: 12-month results of a randomised controlled, efficacy and safety study (CYPRESS) . Br J Ophthalmol. 2022 Sep 1;bjophthalmol-2021-321005).

[0012] 5) Hexgon Optimized Reticular (HORI): Utilizing Hexgon Optimized Reticular (HORI) technology, 540 hexagonal microlenses are embedded within the 35mm diameter of the lens, creating a seamless, integrated reticular array. This technology achieves a lens fill factor of up to 67%. Preliminary studies using this technology have shown that compared to the control group, the spherical equivalent control rate is approximately 70% and the axial length control rate is approximately 50%.

[0013] All of the above-mentioned optical frame lenses used for adolescent myopia prevention and control, including four based on the optical positive defocus theory and one based on the peripheral retinal contrast theory, have a control effect of approximately 60%, demonstrating considerable effectiveness in preventing and controlling myopia in adolescents. However, the optical theories of myopia prevention and control employed by all of the above-mentioned lenses are incomplete, resulting in theoretical limits to the effectiveness of these lenses, whether based on optical defocus or contrast theory.

[0014] The reason for the similar control effects of the aforementioned lenses is that the distribution of the microstructures and microlenses in the lens periphery exhibits deliberate artifacts, i.e., a certain degree of geometric consistency, spatial consistency, or some apparent artificial pattern. Furthermore, the microstructures and microlenses are not complex enough to significantly disrupt vision. For example, in the case of the Xinlexue lens, the visual experience is consistent across all microstructured areas, resulting in a similar visual experience regardless of gaze direction—in other words, the point spread function converges in different directions. Similarly, other lens designs also exhibit clear artifacts and a noticeable pattern in their distribution. Summary of the Invention

[0015] The present invention proposes a new theory of myopia control, namely the optical phase chaos technology of the peripheral retina, and designs myopia prevention and control lenses with fractal microstructures based on this technology.

[0016] The present invention provides a myopia prevention and control spectacle lens with a fractal microstructure, the spectacle lens comprising:

[0017] A lens substrate, wherein the lens substrate is provided with an optical zone and a control zone;

[0018] The optical zone includes a central optical zone, which is an area with a radius of R1 and a center position of the lens as the center of the circle;

[0019] The control zone surrounds the outer side of the central optical zone, and is provided with a microstructure constructed by fractal curves or fractal patterns on the plane of the lens substrate, or a microstructure constructed by fractal curves or fractal patterns between layers of the lens substrate.

[0020] Furthermore, the fractal curve or fractal pattern may be a Peano curve, a Hilbert curve, a Wunderlich curve, a fractal dragon, a leaf fractal, a Koch curve, a Mandelbrot set, a Koch triangle or a Mandelbrot-Julia figure.

[0021] Furthermore, in the optical zone, R1 is 2.5-7.5 mm.

[0022] Furthermore, the control area is in the shape of a circular ring.

[0023] Furthermore, the fractal curve or fractal pattern has a line width ranging from 50 to 1500 μm.

[0024] Furthermore, the total diameter of the lens base is 70-75 mm.

[0025] On the other hand, the present invention also provides a pair of myopia prevention and control glasses, including any of the above-mentioned myopia prevention and control glasses lenses.

[0026] The present invention has the following advantages:

[0027] The myopia prevention and control spectacle lenses with fractal microstructures proposed by the present invention utilize optical phase chaos technology to set a microstructure constructed by fractal curves or fractal patterns on the plane of the lens, or a microstructure constructed by fractal curves or fractal patterns between the layers of the lens, in the control area of ​​the lens. By maximizing the complexity of the peripheral microstructure, the degree of optical perturbation is increased, thereby interfering with the process of myopia progression. Among them, the core concept of optical phase chaos technology is different from optical defocus theory and contrast theory. It mainly relies on the fact that the microstructures distributed around the frame lens must have relative spatial and geometric complexity or non-repeatability. That is, within the limited lens area, artificial deliberateness is avoided as much as possible, and the fractal language of nature is adopted to reduce the regular spatial distribution and microstructure morphological distribution, and increase the complexity of the microstructure itself or the uncertainty of the distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0029] FIG1 is a schematic diagram of the structure of a spectacle lens according to an embodiment of the present invention;

[0030] FIG2 is a schematic diagram of a cross-sectional structure of a spectacle lens having a planar fractal curve or fractal pattern according to an embodiment of the present invention;

[0031] FIG3 is a schematic diagram of a cross-sectional structure of a spectacle lens having an interlayer structured fractal curve or fractal pattern (Hilbert curve) according to an embodiment of the present invention;

[0032] Wherein, the figure numerals are as follows: 1 lens base; 2 optical zone; 3 control zone.

[0033] FIG4 is a schematic diagram of a Hilbert curve tunnel structure according to an embodiment of the present invention;

[0034] FIG5 is a schematic diagram of a peripheral microstructure lens structure constructed with a Hilbert curve according to an embodiment of the present invention;

[0035] FIG6 is a schematic diagram of a peripheral microstructure lens structured with a Peano curve according to an embodiment of the present invention;

[0036] FIG7 is a peripheral microstructure lens having a Wunderlich curve structure according to an embodiment of the present invention;

[0037] FIG8 is a peripheral microstructure lens with a complex Peano curve structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0039] Existing myopia control lenses on the market are all based on the principle of optical defocus. The optical theory used by all these lenses for myopia control is incomplete, which means that the effectiveness of lenses based on both optical defocus and contrast theory in controlling myopia has theoretical limits.

[0040] The similar control effects of these lenses are due to the fact that the lenses used, whether microstructures or microlenses, exhibit deliberate artifacts in the distribution of the lens periphery. This involves a certain degree of geometric consistency, spatial consistency, or some apparent artificial pattern. This results in a largely consistent visual experience when the eye is focused in a particular direction, i.e., similar point spread functions. The microstructures or microlenses are not complex enough at the microscopic level to disrupt vision strongly enough. Therefore, while control effects are generally ideal in the first six months, once neural adaptation occurs, control effectiveness declines significantly.

[0041] After extensive basic and clinical research, the inventors of this application proposed optical phase chaos technology and used nature's fractal language to design the microstructure around the lens. The core idea is not to provide a certain form of microlens, but to create sufficient optical interference in the peripheral field of view so that the retina cannot distinguish the correct growth direction of the eyeball in a short period of time, thereby effectively interfering with the process of deepening myopia.

[0042] As shown in FIG1 , an embodiment of the present invention provides a myopia prevention and control spectacle lens having a fractal microstructure, the spectacle lens comprising:

[0043] A lens substrate 1, wherein the lens substrate 1 is provided with an optical zone 2 and a control zone 3;

[0044] The optical zone 2 includes a central optical zone, which is an area with a radius of R1 and a center of the lens as the center of the circle;

[0045] The control zone 3 surrounds the outer side of the central optical zone, and is provided with a microstructure constructed by fractal curves or fractal patterns on the plane of the lens substrate 1, or a microstructure constructed by fractal curves or fractal patterns between layers of the lens substrate 1.

[0046] The main advantage of the microstructure of the myopia prevention and control lens proposed in the embodiment of the present invention is that when looking in different directions, the visual experience after the light passes through the fractal curve or fractal pattern microstructure is different, thereby effectively interfering with the process of deepening myopia.

[0047] Furthermore, the fractal curve or pattern can be a Peano curve, Hilbert curve, Wunderlich curve, fractal dragon, fractal leaves, Koch curve, Mandelbrot set, Koch triangle, or Mandelbrot-Julia set. For example, a Peano curve, Hilbert curve, Wunderlich curve, fractal dragon, fractal leaves, Koch curve, Mandelbrot set, Koch triangle, or Mandelbrot-Julia set can be used to construct a microstructure around the lens. The fractal curve or pattern provided in the control zone of the present invention can create sufficient optical interference in the peripheral visual field, preventing the retina from quickly discerning the correct growth direction of the eyeball, thereby effectively interfering with the progression of myopia.

[0048] Furthermore, in the optical zone 2, R1 is 2.5-7.5 mm.

[0049] Furthermore, the control area 3 is in a circular shape.

[0050] Furthermore, the line width of the fractal curve or fractal pattern ranges from 50 to 1500 μm, and the ratio of the width of the black and white lines is arbitrary.

[0051] Preferably, the total diameter of the lens base is 70-75 mm.

[0052] Furthermore, the cross-sectional shape relationship between the microstructure and the lens substrate can be a square wave, a triangle, a trapezoid, a convex lens, or a concave lens. Other fractal geometric shapes can also be used.

[0053] In this embodiment of the present invention, the optical zone of the spectacle lens is primarily used to correct refractive errors. The peripheral control zone of the spectacle lens utilizes a microstructure constructed using fractal curves or patterns. This creates sufficient optical interference in the peripheral visual field, preventing the retina from quickly discerning the correct eye growth direction, thereby effectively interfering with the progression of myopia.

[0054] In a preferred embodiment of the present invention, taking the microstructure of a fractal curve or a fractal pattern on the plane of a spectacle lens as an example, the cross section of the spectacle lens is shown in FIG2 below.

[0055] In a preferred embodiment of the present invention, a microstructure constructed between layers of a spectacle lens using fractal curves or patterns (Hilbert curves) is shown in Figure 3 below, showing a cross-section of the lens. The Hilbert curve can be used to fill a three-dimensional space, forming a tunnel by filling the control area around the lens' periphery with interlayer fractal curves or patterns.

[0056] In the embodiments of the present invention, the spectacle lenses all have thickness. Microstructures are created between lens layers to maximize optical interface disturbance. Interlayer microstructure lenses employ fractal curves or patterns, specifically by constructing microtunnels between layers around the lens perimeter using fractal curves or patterns, such as a Hilbert curve, as shown in Figure 4 below. Laser engraving technology is employed, enabling the smallest tunnel structure to reach tens of microns.

[0057] The present invention will be described in detail below with reference to the embodiments.

[0058] Example 1 Hilbert curve structured peripheral microstructure lens

[0059] As shown in FIG5 , a convex Hilbert fractal curve is produced on the lens substrate.

[0060] The curve width is 500 μm, with a 1:1 ratio of black and white lines. The cross-section of the curve is spherical, the cross-sectional cylindrical lens has a refractive power of +3.00 DC, and the lens refractive index is 1.74. The calculated sagittal height of the Hilbert fractal curve is 0.13 μm. Taking into account the coating process accuracy and the submersion of microstructures during the coating process, the cross-sectional sagittal height of the curve can be reduced to 0.3-0.4 μm.

[0061] Example 2: Peripheral microstructure lens with Peano curve structure

[0062] As shown in FIG6 , a Peano fractal curve that is concave into the lens substrate is produced on the lens substrate.

[0063] The curve width is 800 μm, with a 1:1 ratio of black and white lines. The cross-section of the curve is spherical, the cross-sectional cylindrical power is -5.00 DC, and the lens refractive index is 1.67. The calculated sag of the Peano fractal curve is 0.60 μm. Taking into account the coating process accuracy and the submersion of microstructures during the coating process, the cross-sectional sag of the curve can be reduced to 1-1.3 μm.

[0064] Example 3 Interlayer microstructure lens constructed with Hilbert curve.

[0065] As shown in Figure 3, laser engraving technology is used to construct a Hilbert tunnel with a diameter of 50 μm, filling the interlayer at the periphery of the lens.

[0066] Example 4: Peripheral microstructure lens with Wunderlich curve structure.

[0067] As shown in FIG7 , a Wunderlich fractal curve convex to the lens substrate is produced.

[0068] The curve width is 500 μm, with a 1:1 ratio of black and white lines. The cross-section of the curve is spherical, the cross-sectional cylindrical power is +3.00 DC, and the lens refractive index is 1.74. The calculated sagittal height of the Wunderlich fractal curve is 0.13 μm. Taking into account the coating process accuracy and the submersion of microstructures during the coating process, the cross-sectional sagittal height of the curve can be reduced to 0.3-0.4 μm.

[0069] Example 5: Peripheral microstructure lens with complex Peano curve structure

[0070] As shown in Figure 8, a complex Peano fractal curve is produced on the lens substrate. This curve is characterized by different densities, inconsistent line widths, and a complex graphic structure.

[0071] The curve line width is 400-800 μm, the cross-section is spherical, the microstructure cross-section has a continuous cylindrical refractive power of +6.00 DC, and the lens refractive index is 1.67. The calculated sag height of the Peano fractal curve is 0.18-0.72 μm. Taking into account the coating process accuracy and the submersion of the microstructure during the coating process, the sag height of the curve cross-section can be reduced to 0.5-1.3 μm.

[0072] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A myopia prevention and control spectacle lens with a fractal microstructure, characterized in that: The spectacle lenses include: A lens substrate, wherein an optical area and a control area are provided on the lens substrate; The optical zone includes a central optical zone, which is an area with a center of the lens as the center and a radius of R1; The control zone surrounds the outside of the central optical zone, and a microstructure constructed by fractal curves or fractal patterns on the plane of the lens substrate, or a microstructure constructed by fractal curves or fractal patterns between layers of the lens substrate (1) is provided in the control zone.

2. The myopia prevention and control spectacle lens according to claim 1, characterized in that: The fractal curve or fractal pattern may be a Peano curve, a Hilbert curve, a Wunderlich curve, a fractal dragon, a leaf fractal, a Koch curve, a Mandelbrot set, a Koch triangle or a Mandelbrot-Julia figure.

3. The myopia prevention and control spectacle lens according to claim 1, characterized in that: In the optical zone, R1 is 2.5-7.5 mm.

4. The myopia prevention and control spectacle lens according to claim 1, characterized in that: The control area is in the shape of a circular ring.

5. The myopia prevention and control spectacle lens according to claim 1, characterized in that: The fractal curve or fractal pattern has a line width ranging from 50 to 1500 μm.

6. The myopia prevention and control spectacle lens according to claim 1, characterized in that: The total diameter of the lens base is 70-75 mm.

7. A pair of myopia prevention and control glasses, characterized in that: Including the myopia prevention and control spectacle lenses according to any one of claims 1 to 6.

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