A multi-focal lens

Abstract

The application discloses a multifocal lens, which comprises a central region and an overcorrection region surrounding the central region, the multifocal lens has a first preset optical power at a central position of the central region, the first preset optical power is higher than a prescribed focal power; the multifocal lens has a second preset optical power at a first position of the overcorrection region, the second preset optical power is lower than the prescribed focal power. The multifocal lens of the embodiment of the application sets the central region as a high-addition region, so that the central region can generate myopic defocus, and the myopic defocus is generated in a wide area of the retina, which is helpful to control the myopia development of the user's eyes; meanwhile, the overcorrection region is further arranged around the central region, and the overcorrection region is set to have a negative addition, so that the overcorrection region can balance the influence of the high addition of the central region, and clear central vision is generated, thereby the control of the myopic defocus is improved while the central vision is maintained.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and more particularly to a multifocal lens. Background Technology

[0002] In existing multifocal lens technology, lens design commonly employs spherical or conical curves. These traditional methods have significant limitations in lens construction. First, the power curves formed using these curves are typically monotonous, resulting in a uniform change in power across the entire curve. This makes it difficult to effectively control myopic defocus without sacrificing central vision. Compromises are often necessary between improving visual acuity and controlling myopic defocus, especially when dealing with power variations in the central and peripheral visual zones. This limits the flexibility and adaptability of lenses in addressing different visual needs. Summary of the Invention

[0003] This invention provides a multifocal lens to improve control of myopic defocus while maintaining central vision.

[0004] This invention provides a multifocal lens, including an optical region;

[0005] The optical region includes a central region and an overcorrected region surrounding the central region;

[0006] The multifocal lens has a first preset optical power at the center of the central region, and the first preset optical power is higher than the prescription optical power.

[0007] The multifocal lens has a second preset power at a first position in the overcorrected region, and the second preset power is lower than the prescription power.

[0008] Optionally, the difference between the first preset optical power and the prescription optical power is the first added optical power;

[0009] The first added light intensity is P1, where P1 ≥ 1.5D.

[0010] Optionally, the difference between the second preset optical power and the prescription optical power is the second added optical power;

[0011] The second added light intensity is P2, where -4D≤P2≤-1D.

[0012] Optionally, the distance between the first position and the center position of the central region is L1, wherein 0.75mm≤L1≤1.25mm.

[0013] Optionally, the multifocal lens further includes a primary refractive area surrounding the overcorrection region and a secondary refractive area surrounding the primary refractive area;

[0014] The multifocal lens has a third preset optical power at the second position of the primary light-adding area;

[0015] The multifocal lens has a fourth preset optical power at the third position in the secondary light-adding region;

[0016] Both the third preset optical power and the fourth preset optical power are higher than the prescription optical power, and the third preset optical power and the fourth preset optical power are different.

[0017] Optionally, the difference between the third preset optical power and the prescription optical power is the third added optical power;

[0018] The difference between the fourth preset optical power and the prescription optical power is the fourth added optical power;

[0019] The third luminous intensity is P3, and the fourth luminous intensity is P4, wherein P3 ≥ +1D and P4 ≥ +2D.

[0020] Optionally, the difference between the third preset optical power and the prescription optical power is the third added optical power;

[0021] The difference between the fourth preset optical power and the prescription optical power is the fourth added optical power;

[0022] The third luminous intensity is P3, and the fourth luminous intensity is P4, wherein P4 > P3.

[0023] Optionally, the difference between the first preset optical power and the prescription optical power is the first added optical power;

[0024] The difference between the third preset optical power and the prescription optical power is the third added optical power;

[0025] The difference between the fourth preset optical power and the prescription optical power is the fourth added optical power;

[0026] The first luminous intensity is P1, the third luminous intensity is P3, and the fourth luminous intensity is P4, wherein P4 > P1 and P3 < P1.

[0027] Optionally, the distance between the second position and the center position of the central region is L2, and the distance between the third position and the center position of the central region is L3, wherein 1.5mm≤L2≤2mm, 2.5mm≤L3≤3mm.

[0028] Optionally, the diameter of the optical region is d1, where 4mm ≤ d1 ≤ 6mm.

[0029] In this embodiment of the multifocal lens, a first preset optical power higher than the prescription optical power is set at the center of the central region, i.e., the central region is designated as a high-light-added region. This allows the central region to generate myopic defocus. Since the central region corresponds to the center of the pupil, it affects most of the retina, thus generating myopic defocus over a wide area of ​​the retina, which helps control the progression of myopia in the user's eyes. Simultaneously, an overcorrected region is also provided around the central region. The overcorrected region has a first position, at which the multifocal lens has a second preset optical power lower than the prescription optical power, i.e., the overcorrected region has a negative optical power. This allows the overcorrected region to balance the visual impact of the high-light-added central region, producing clear central vision, thereby improving the control of myopic defocus while maintaining central vision.

[0030] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of a multifocal lens provided in an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the optical power distribution of a multifocal lens provided in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the optical power distribution of another multifocal lens provided in an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the optical power distribution of another multifocal lens provided in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the MTF of a multifocal lens provided in an embodiment of the present invention. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] Figure 1 This is a schematic diagram of a multifocal lens provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the optical power distribution of a multifocal lens provided in an embodiment of the present invention, wherein, Figure 2 An optical power curve is shown, with the horizontal axis representing the radius in mm and the vertical axis representing the added power in D. Added power refers to the difference between the optical power at the current position and the prescription power. An added power of 0 indicates that the optical power at that position is equal to the prescription power.

[0040] The prescription focal length can be 0 or a negative focal length that provides the best corrected visual acuity for myopic patients. The specific prescription focal length can be determined by a doctor or optometrist.

[0041] like Figure 1 and Figure 2 As shown, the multifocal lens provided in this embodiment of the invention includes an optical region 10, which includes a central region 11 and an overcorrection region 12 surrounding the central region 11. The multifocal lens has a first preset optical power at the center position O1 of the central region 11, which is higher than the prescription optical power. The multifocal lens has a second preset optical power at the first position X1 of the overcorrection region 12, which is lower than the prescription optical power.

[0042] The multifocal lenses provided in this embodiment of the invention include corneal contact lenses, which can be specifically applied to orthokeratology lenses, rigid corneal contact lenses, or soft corneal contact lenses, etc. This embodiment of the invention does not make specific limitations in this regard.

[0043] Continue to refer to Figure 1 and Figure 2 The multifocal lens includes an optical zone 10, which can produce a myopic defocus effect while being used for conventional vision correction (e.g., the optical zone 10 can have a negative optical power to correct existing myopic distance vision), slowing down axial elongation and controlling the development of myopia in the user's eyes.

[0044] It should be noted that the optical power mentioned in the embodiments of the present invention refers to the difference in refractive power of the cornea after it has been reshaped by multifocal lenses compared with that of the cornea before treatment.

[0045] Furthermore, the optical region 10 includes a central region 11, which may be located at the center of the optical region 10. The central region 11 has a central position O1, which is located at the geometric center of the central region 11. At the central position O1 of the central region 11, the multifocal lens has a first preset optical power, wherein the first preset optical power refers to the optical power specified at the central position O1.

[0046] Lenses used to correct myopia typically do not have a high-power area (i.e., an area with a power higher than the prescription power) in the center of the lens. The center of the lens is usually used to place the prescription power, so that the center area matches the existing myopic distance visual conditions, thereby providing central myopic distance vision correction.

[0047] In this embodiment, at the center position O1 of the central region 11, a first preset optical power is set higher than the prescription optical power, that is, the central region 11 is set as a high-light region so that the central region 11 can generate myopic defocus. Since the central region 11 corresponds to the center of the pupil, the central region 11 will affect most of the retina, thereby generating myopic defocus in a wide area of ​​the retina, which helps to control the development of myopia in the user's eyes.

[0048] Furthermore, an overcorrected region 12 is provided around the central region 11. The overcorrected region 12 has a first position X1. At the first position X1, the multifocal lens has a second preset optical power, wherein the second preset optical power refers to the optical power specified at the first position X1.

[0049] In this embodiment, the second preset optical power is set to be lower than the prescription optical power, that is, the overcorrected area 12 is set to have a negative added power, so that the overcorrected area 12 can balance the visual impact caused by the high added power of the central area 11, and produce clear central vision, thereby improving the control of myopia defocus while maintaining central vision.

[0050] It should be noted that the embodiments of the present invention do not impose any particular restrictions on the focal length variation between the center position O1 of the central region 11 and the first position X1 of the overcorrected region 12.

[0051] like Figure 2 As shown, the focal length variation between the center position O1 of the central region 11 and the first position X1 of the overcorrected region 12 can be a specified form. Figure 2 In the middle, the focal length variation between the center position O1 of the central region 11 and the first position X1 of the overcorrected region 12 is in the form of a natural and continuous curve, which can provide a more uniform and high-quality visual experience.

[0052] Figure 3 This is a schematic diagram of the optical power distribution of another multifocal lens provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the optical power distribution between the center position O1 of the central region 11 and the first position X1 of the overcorrected region 12 can be oscillating, or the optical power distribution between the center position O1 of the central region 11 and the first position X1 of the overcorrected region 12 can decrease in a stepwise manner.

[0053] Figure 4 This is a schematic diagram of the optical power distribution of another multifocal lens provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the optical power distribution between the center position O1 of the central region 11 and the first position X1 of the overcorrected region 12 can be a natural continuation of the focal power change between the first preset optical power and the second preset optical power. At this time, the focal power change between the center position O1 of the central region 11 and the first position X1 of the overcorrected region 12 can be in the form of a straight line.

[0054] Furthermore, such as Figures 2-4 As shown, the central region 11 and the overcorrected region 12 can be arranged adjacent to each other. The added light intensity at the boundary between the central region 11 and the overcorrected region 12 can be 0, that is, the optical power at the boundary between the central position O1 and the overcorrected region 12 is equal to the prescription power.

[0055] At this time, the optical power at each position within the central region 11 can be higher than the prescription power, so that the central region 11 will produce myopic defocus on most of the retina, which helps to control the development of myopia in the user's eyes.

[0056] At the same time, the optical power at each position within the overcorrected area 12 can be lower than the prescription power, so that the overcorrected area 12 can balance the visual impact caused by the high light in the central area 11, producing clear central vision, thereby improving the control of myopic defocus while maintaining central vision.

[0057] It should be noted that in the optical region 10 of the multifocal lens, the optical power can be symmetrically distributed around the center position O1 of the optical region 10. Figures 2-4 The case of one side is shown only as an example.

[0058] Continue to refer to Figures 2-4 Optionally, the difference between the first preset optical power and the prescription optical power is the first added optical power, and the first added optical power is P1, where P1 ≥ 1.5D.

[0059] The first added light intensity refers to the additional light intensity of the first preset light intensity at the center position O1 of the optical zone 10 relative to the prescription light intensity.

[0060] In this embodiment, by setting the first luminous intensity P1 to be greater than or equal to 1.5D, the central region 11 has a high luminous intensity, which enables the central region 11 to generate sufficient myopic defocus, thereby generating sufficient myopic defocus over a wide area of ​​the retina, which helps to control the development of myopia in the user's eyes.

[0061] Continue to refer to Figures 2-4 Optionally, the difference between the second preset optical power and the prescription optical power is the second added optical power, which is P2, where -4D≤P2≤-1D.

[0062] The second added power refers to the additional optical power at the first position X1 of the overcorrected region 12 relative to the prescription optical power.

[0063] In this embodiment, by setting the second illuminance P2 to be greater than or equal to -4D and less than or equal to -1D, the negative illuminance of the overcorrected region 12 is reasonably set, so that the overcorrected region 12 can better balance the influence of the high illuminance of the central region 11, produce clear central vision, and improve central vision.

[0064] Continue to refer to Figures 2-4 Optionally, the distance between the first position X1 and the center position O1 of the central region 11 is L1, where 0.75mm≤L1≤1.25mm.

[0065] In this embodiment, by reasonably setting the distance L1 between the first position X1 of the overcorrected region 12 and the center position O1, the incident light beam can be irradiated in the area within the appropriate field of view of the retina after passing through the first position X1 with the second preset optical power. This can better balance the influence of the high-precision light in the center region 11, produce clear central vision, and improve central vision.

[0066] One option is to set L1 = 1mm to provide better central vision, but this is not the only option.

[0067] Continue to refer to Figures 1-4Optionally, the multifocal lens provided in this embodiment of the invention further includes a primary light-adding region 13 surrounding the overcorrection region 12 and a secondary light-adding region 14 surrounding the primary light-adding region 13. The multifocal lens has a third preset power at a second position X2 in the primary light-adding region 13, and a fourth preset power at a third position X3 in the secondary light-adding region 14. Both the third and fourth preset powers are higher than the prescription power, and the third and fourth preset powers are different.

[0068] Specifically, such as Figures 1-4 As shown, a primary light-adding region 13 is also provided around the overcorrection region 12. The primary light-adding region 13 has a second position X2. At the second position X2, the multifocal lens has a third preset optical power, wherein the third preset optical power refers to the optical power specified at the second position X2.

[0069] Furthermore, the third preset optical power is set higher than the prescription optical power, that is, the first-level light-adding area 13 is set as the light-adding area, which can form defocus around the retina, which is beneficial to control the progression of myopia.

[0070] Meanwhile, a secondary light-adding area 14 is also provided around the primary light-adding area 13. The secondary light-adding area 14 has a third position X3. At the third position X3, the multifocal lens has a fourth preset optical power, wherein the fourth preset optical power refers to the optical power specified at the third position X3.

[0071] Furthermore, the fourth preset optical power is set higher than the prescription optical power, that is, the secondary light-adding area 14 is set as the light-adding area, which can form defocus around the retina, which is beneficial to control the progression of myopia.

[0072] In this embodiment, three light-adding areas (central area 11, primary light-adding area 13, and secondary light-adding area 14) are used to obtain strong peripheral retinal defocus, especially in the area around 15°, where a defocus amount of about -3D can be achieved, thereby better controlling the development of myopia.

[0073] Furthermore, the third preset optical power and the fourth preset optical power are different, which, while creating defocus around the retina, helps to accommodate a wider range of pupil sizes.

[0074] It should be noted that the embodiments of the present invention do not impose any particular restrictions on the focal length variation between the first position X1 of the overcorrection region 12 and the second position X2 of the primary illumination region 13.

[0075] like Figure 2 As shown, the focal length variation between the first position X1 of the overcorrection region 12 and the second position X2 of the primary illumination region 13 can be a specified form, for example, in Figure 2In the process, the focal length variation between the first position X1 of the overcorrection area 12 and the second position X2 of the primary illumination area 13 is in the form of a natural and continuous curve, which can provide a more uniform and high-quality visual experience.

[0076] Continue to refer to Figure 3 The optical power distribution between the first position X1 of the overcorrected region 12 and the second position X2 of the primary light-adding region 13 can be oscillating, or the optical power distribution between the first position X1 of the overcorrected region 12 and the second position X2 of the primary light-adding region 13 can increase in a stepwise manner.

[0077] Continue to refer to Figure 4 The optical power distribution between the first position X1 of the overcorrection area 12 and the second position X2 of the primary light-adding area 13 can be a natural continuation of the focal power change between the second preset optical power and the third preset optical power. At this time, the focal power change between the first position X1 of the overcorrection area 12 and the second position X2 of the primary light-adding area 13 can be in the form of a straight line.

[0078] Furthermore, such as Figures 2-4 As shown, the overcorrected region 12 and the primary light-adding region 13 can be arranged adjacent to each other. The light-adding intensity at the boundary between the overcorrected region 12 and the primary light-adding region 13 can be 0, that is, the optical power at the boundary between the overcorrected region 12 and the primary light-adding region 13 is equal to the prescription power.

[0079] At this time, the optical power at each position within the primary light-adding area 13 can be higher than the prescription power, so that the primary light-adding area 13 can produce myopic defocus on a larger area of ​​the retina, which helps to control the development of myopia in the user's eyes.

[0080] Furthermore, the embodiments of the present invention do not impose any particular restrictions on the focal length variation between the second position X2 of the primary illumination region 13 and the third position X3 of the secondary illumination region 14.

[0081] like Figure 2 As shown, the focal length variation between the second position X2 of the primary illumination region 13 and the third position X3 of the secondary illumination region 14 can be a specified form, for example, in... Figure 2 In the middle, the focal length change between the second position X2 of the primary lighting area 13 and the third position X3 of the secondary lighting area 14 is in the form of a natural and continuous curve, which can provide a more uniform and high-quality visual experience.

[0082] Continue to refer to Figure 3 The optical power distribution between the second position X2 of the primary lighting region 13 and the third position X3 of the secondary lighting region 14 can be oscillating, or the optical power distribution between the second position X2 of the primary lighting region 13 and the third position X3 of the secondary lighting region 14 can increase in a stepwise manner.

[0083] Continue to refer to Figure 4 The optical power distribution between the second position X2 of the primary illumination region 13 and the third position X3 of the secondary illumination region 14 can be tortuous. In this case, the change in optical power between the first position X1 of the overcorrection region 12 and the second position X2 of the primary illumination region 13 can be in the form of a broken line.

[0084] Furthermore, such as Figures 2-4 As shown, the primary light-adding area 13 and the secondary light-adding area 14 can be set adjacent to each other. The light-adding intensity at the boundary between the primary light-adding area 13 and the secondary light-adding area 14 is p1, which can be greater than 0. That is, the optical power at the boundary between the primary light-adding area 13 and the secondary light-adding area 14 is higher than the prescription power, which is beneficial to generate myopic defocus on a larger area of ​​the retina and helps to control the development of myopia in the user's eyes.

[0085] Optional, such as Figure 2 and Figure 4 As shown, the light intensity p1 at the junction between the primary light-adding region 13 and the secondary light-adding region 14 can be less than the optical power at the second position X2 of the primary light-adding region 13, and the light intensity p1 at the junction between the primary light-adding region 13 and the secondary light-adding region 14 is less than the optical power at the third position X3 of the secondary light-adding region 14. In this way, while creating defocus at the periphery of the retina, it is beneficial to adapt to a larger range of pupil sizes.

[0086] It is important to note that Figure 1 The various regions in the diagram are represented as concentric circles. These regions may include any suitable circular or non-circular shape, such as an ellipse. This embodiment of the invention does not specifically limit this.

[0087] Continue to refer to Figures 2-4 Optionally, the difference between the third preset optical power and the prescription optical power is the third added optical power, and the difference between the fourth preset optical power and the prescription optical power is the fourth added optical power. The third added optical power is P3, and the fourth added optical power is P4, where P3 ≥ +1D and P4 ≥ +2D.

[0088] Wherein, the third added light intensity P3 refers to the additional light intensity of the third preset light intensity at the second position X2 of the primary light intensity region 13 relative to the prescription light intensity, and the fourth added light intensity P4 refers to the additional light intensity of the fourth preset light intensity at the third position X3 of the secondary light intensity region 14 relative to the prescription light intensity.

[0089] In this embodiment, by setting the third illumination intensity P3 to be greater than or equal to +1D and the fourth illumination intensity P4 to be greater than or equal to +2D, the illumination intensity of the primary illumination area 13 and the secondary illumination area 14 is reasonably set, so that the primary illumination area 13 and the secondary illumination area 14 can produce strong peripheral retinal defocus, especially in the area around 15°, which can reach a defocus amount of about -3D, which helps to control the myopia development of the user's eyes.

[0090] Continue to refer to Figures 2-4 Optionally, the difference between the third preset optical power and the prescription optical power is the third added optical power, and the difference between the fourth preset optical power and the prescription optical power is the fourth added optical power. The third added optical power is P3, and the fourth added optical power is P4, where P4 > P3.

[0091] Specifically, by setting the fourth illumination power P4 to be greater than the third illumination power P3, the illumination power of the primary illumination area 13 and the secondary illumination area 14 can be reasonably set, so that the primary illumination area 13 and the secondary illumination area 14 can produce better peripheral retinal defocus, especially in the area around 15°, which can achieve a defocus amount of about -3D, which helps to control the myopia development of the user's eyes. At the same time, it is also conducive to adapting to a wider range of pupil sizes.

[0092] Continue to refer to Figures 2-4 Optionally, the difference between the first preset optical power and the prescription optical power is the first added optical power, the difference between the third preset optical power and the prescription optical power is the third added optical power, and the difference between the fourth preset optical power and the prescription optical power is the fourth added optical power. The first added optical power is P1, the third added optical power is P3, and the fourth added optical power is P4, where P4 > P1 and P3 < P1.

[0093] Specifically, by setting the fourth illumination power P4 to be greater than the first illumination power P1 and the third illumination power P3 to be less than the first illumination power P1, the illumination power of the three illumination areas (central area 11, primary illumination area 13, and secondary illumination area 14) is reasonably set, so that the central area 11, primary illumination area 13, and secondary illumination area 14 can produce better retinal defocus, especially in the area around 15°, where a defocus amount of about -3D can be achieved, which helps to control the myopia development of the user's eyes.

[0094] Continue to refer to Figures 2-4 Optionally, the distance between the second position X2 and the center position O1 of the central region 11 is L2, and the distance between the third position X3 and the center position O1 of the central region 11 is L3, wherein 1.5mm≤L2≤2mm and 2.5mm≤L3≤3mm.

[0095] In this embodiment, by reasonably setting the distance L2 between the second position X2 and the center position O1 of the central region 11, and the distance L3 between the third position X3 and the center position O1 of the central region 11,

[0096] The incident light beam can be directed to a region within a suitable field of view of the retina after passing through a second position X2 with a third preset optical power and a third position X3 with a fourth preset optical power. This allows the primary illumination region 13 and the secondary illumination region 14 to produce better peripheral defocus of the retina, especially in the region around 15°, where a defocus amount of about -3D can be achieved, which helps to control the development of myopia in the user's eyes.

[0097] Among them, L2 = 1.75mm and L3 = 2.75mm can be set to provide better peripheral defocus of the retina, but it is not limited to this.

[0098] Continue to refer to Figure 1 Optionally, the diameter of the optical region 10 is d1, where 4mm≤d1≤6mm.

[0099] By setting the diameter d1 of the optical region 10 to satisfy 4mm≤d1≤6mm, the optical region 10 can have sufficient space to implement the complex optical power curve in this invention, while also taking into account the comfort and practicality of multifocal lenses.

[0100] It should be noted that the multifocal lenses provided in the embodiments of the present invention are not limited to those described above. Figures 2-4 The power curve shown illustrates that precise control of the power curve is crucial in the design of the base curve (BC) of multifocal lenses. By meticulously adjusting the power curve, the optical performance of the lens can be optimized, especially in the power design of the 4 mm central diameter region and the annular region 1 mm from the center. This improves the control of myopia defocus while maintaining central vision. In particular, around 15°, a defocus of about -3D can be achieved, thus better controlling the progression of myopia.

[0101] In this embodiment of the invention, the optical power curve is optimized, which can maintain central vision and improve the control of myopia defocus, while also simulating the complex optical power curve in the above embodiment by using multiple aspherical conic section arcs.

[0102] For example, it can be seen from Figure 2 The radius of curvature R at each position on the optical power curve is calculated, where the radius of curvature R satisfies the formula:

[0103] R = 337.5 / (K+P+A+JF);

[0104] Where K represents corneal curvature, P represents prescription power, A represents added power, and JF represents overcorrection factor, which can be set to -0.75D.

[0105] For example, for the corneal center point (i.e. the center of the optical zone), K = 43, P = -3, A = 0, JF = 0.75, then R = 337.5 / (43-3+0-0.75) = 8.5987mm.

[0106] For a position 1 mm from the center of the cornea, A = -2, then R = 337.5 / (43-3-2-0.75) = 9.0604 mm.

[0107] It should be noted that the values ​​of A mentioned above are for illustrative purposes only and do not constitute a limitation of the present invention.

[0108] For a user, the prescription power P, corneal curvature K, and overcorrection coefficient JF are all known and given. By simply providing the optical power curve provided in the embodiment of the present invention, the added power values ​​at different positions of the multifocal lens can be obtained, and the radius of curvature on the BC arc of the multifocal lens can be calculated.

[0109] Based on the above method of using multiple circular arcs to simulate optical power curves, the specific optical physical parameters of the multifocal lens provided in the embodiments of the present invention will be described in detail below with a feasible implementation method.

[0110] like Figure 2 As shown, by fitting 12 aspherical conic section arcs, each arc segment being 0.25 mm wide, the following parameters can be obtained:

[0111] The first arc has a radius of 0mm-0.25mm, a radius of curvature R = 7.829mm, and an aspheric coefficient Q = 0.001.

[0112] The second arc has a radius of 0.25mm-0.5mm, a radius of curvature R = 8.099mm, and an aspheric coefficient Q = 0.001.

[0113] The third arc has a radius of 0.5mm-0.75mm, a radius of curvature R = 8.387mm, and an aspheric coefficient Q = 0.000.

[0114] The fourth arc has a radius of 0.75mm-1mm, a radius of curvature R = 8.510mm, and an aspheric coefficient Q = 0.001.

[0115] The fifth arc has a radius of 1mm-1.25mm, a radius of curvature R = 8.460mm, and an aspheric coefficient Q = 0.001.

[0116] The sixth arc has a radius of 1.25mm-1.5mm, a radius of curvature R = 8.327mm, and an aspheric coefficient Q = 0.000.

[0117] The 7th arc has a radius of 1.5mm-1.75mm, a radius of curvature R = 8.212mm, and an aspheric coefficient Q = -0.000.

[0118] The 8th arc has a radius of 1.75mm-2mm, a radius of curvature R = 8.166mm, and an aspheric coefficient Q = -0.002.

[0119] The 9th arc has a radius of 2mm-2.25mm, a radius of curvature R = 8.174mm, and an aspheric coefficient Q = -0.004.

[0120] The 10th arc has a radius of 2.25mm-2.5mm, a radius of curvature R = 8.171mm, and an aspheric coefficient Q = -0.003.

[0121] The 11th arc has a radius of 2.5mm-2.75mm, a radius of curvature R = 8.113mm, and an aspheric coefficient Q = -0.003.

[0122] The 12th arc has a radius of 2.75mm-3mm, a radius of curvature R = 8.052mm, and an aspherical coefficient Q = -0.001.

[0123] In this embodiment, multi-segment circular arcs are used to simulate optical power curves, which can create different optical focal length regions on the multifocal lens. By adjusting the area size and the amount of added light in each region, fine optical power control can be performed in different regions of the multifocal lens, achieving more flexible and precise optical power adjustment. Especially when dealing with changes in optical power between the central and peripheral viewing areas, it can provide a more uniform and high-quality visual experience.

[0124] Furthermore, Figure 5 This is a schematic diagram of the modulation transfer function (MTF) of a multifocal lens provided in an embodiment of the present invention, wherein the horizontal axis represents the spatial frequency in lp / mm; and the vertical axis represents the normalized MTF, which has no unit. Figure 5 In the case of simulated -3D myopia, the visual acuity calculation algorithm based on MTF yields a logMAR visual acuity of -0.0302, which is better than the decimal visual acuity of 1.0, providing clear central vision. At the same time, the myopic defocus at a 15° angle of view can be calculated as -3.1732D, thereby improving the control of myopic defocus.

[0125] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0126] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A multifocal lens, characterized in that, Including the optical area; The optical region includes a central region and an overcorrected region surrounding the central region; The multifocal lens has a first preset optical power at the center of the central region, and the first preset optical power is higher than the prescription optical power. The multifocal lens has a second preset power at a first position in the overcorrection region, the second preset power being lower than the prescription power; the second preset power has a minimum power. The optical power at each location within the central region is higher than the prescription optical power; the optical power at each location within the overcorrected region is lower than the prescription optical power, in order to balance the visual impact caused by the high light intensity in the central region; The central region and the overcorrected region are arranged adjacent to each other, and the optical power at the boundary between the central region and the overcorrected region is equal to the prescription power; The difference between the first preset optical power and the prescription optical power is the first added optical power; The first added light intensity is P1, where P1 ≥ 1.5D; The difference between the second preset optical power and the prescription optical power is the second added optical power; The second added light intensity is P2, where -4D≤P2≤-1D.

2. The multifocal lens according to claim 1, characterized in that, The distance between the first position and the center position of the central region is L1, where 0.75mm≤L1≤1.25mm.

3. The multifocal lens according to claim 1, characterized in that, The multifocal lens also includes a primary light-adding region surrounding the overcorrection region and a secondary light-adding region surrounding the primary light-adding region; The multifocal lens has a third preset optical power at the second position of the primary light-adding area; The multifocal lens has a fourth preset optical power at the third position in the secondary light-adding region; Both the third preset optical power and the fourth preset optical power are higher than the prescription optical power, and the third preset optical power and the fourth preset optical power are different.

4. The multifocal lens according to claim 3, characterized in that, The difference between the third preset optical power and the prescription optical power is the third added optical power; The difference between the fourth preset optical power and the prescription optical power is the fourth added optical power; The third luminous intensity is P3, and the fourth luminous intensity is P4, wherein P3 ≥ +1D and P4 ≥ +2D.

5. The multifocal lens according to claim 3, characterized in that, The difference between the third preset optical power and the prescription optical power is the third added optical power; The difference between the fourth preset optical power and the prescription optical power is the fourth added optical power; The third luminous intensity is P3, and the fourth luminous intensity is P4, wherein P4 > P3.

6. The multifocal lens according to claim 3, characterized in that, The difference between the third preset optical power and the prescription optical power is the third added optical power; The difference between the fourth preset optical power and the prescription optical power is the fourth added optical power; The first luminous intensity is P1, the third luminous intensity is P3, and the fourth luminous intensity is P4, wherein P4 > P1 and P3 < P1.

7. The multifocal lens according to claim 3, characterized in that, The distance between the second position and the center position of the central region is L2, and the distance between the third position and the center position of the central region is L3, wherein 1.5mm≤L2≤2mm, 2.5mm≤L3≤3mm.

8. The multifocal lens according to claim 1, characterized in that, The diameter of the optical region is d1, where 4mm≤d1≤6mm.

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