Eyeglass lens and method for designing an eyeglass lens

Abstract

To provide an eyeglass lens with which, while applying DIMS, it is possible to improve contrast.SOLUTION: Provided is an eyeglass lens that includes: a base region in which a light beam incident from an object-side plane is emitted from an eyeball-side plane and is converged at a prescribed position A on a retina via the eyeball; a plurality of defocus regions which have the characteristic of converging the light beam at a position B which is closer to the object side than the position A, or a position C which is closer to the side that is opposite to the position B as seen from the position A; and a transfer region which is provided at a boundary between the base region and the defocus regions and moderates a change of curvature between the base region and the defocus regions.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a spectacle lens and a method for designing a spectacle lens. [Background technology]

[0002] Spectacle lenses that suppress the progression of refractive errors such as myopia include those that have multiple island-shaped regions formed on the lens, each with a refractive power that is more positive than the prescribed refractive power (see, for example, Patent Document 1). The spectacle lens described in Patent Document 1 is also called a DIMS (Defocus Incorporated Multiple Segments) spectacle lens, or DIMS for short. Hereinafter, these island-shaped regions will be referred to as defocus regions.

[0003] According to the eyeglass lens configuration disclosed in Patent Document 1, the light beam that passes through the island region is focused at a position in front of the retina, thereby suppressing the progression of myopia. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2017 / 0131567 Summary of the Invention [Problem to be solved by the invention]

[0005] While DIMS eyeglass lenses have the above advantages, they tend to have lower contrast compared to regular single-vision lenses due to the effect of the defocus area. An object of one embodiment of the present invention is to provide eyeglass lenses that can reduce the above problems and improve contrast compared to known DIMS eyeglass lenses. [Means for solving the problem]

[0006] A first aspect of the present invention is a base region that causes a light beam incident from the object-side surface to exit from the eyeball-side surface and converge at a predetermined position A on the retina via the eyeball; a plurality of defocus areas each having a property of converging a light beam to a position B closer to the object side than the position A, or to a position C on the opposite side of the position B as viewed from the position A; a transfer region provided at a boundary between the base region and the defocus region, which makes the change in curvature between the base region and the defocus region gentle; The eyeglass lens comprises:

[0007] A second aspect of the present invention is In the eyeglass lens according to the first aspect, the width of the transfer region is 5.0% or more and 8.5% or less of the diameter of the defocus region.

[0008] A third aspect of the present invention is The eyeglass lens according to the first or second aspect, wherein at least a portion of the transfer region is configured to gradually change the curvature between the base region and the defocus region by changing the amount of sag of the lens substrate.

[0009] A fourth aspect of the present invention is The eyeglass lens according to any one of the first to third aspects, wherein the sag amount Z at the midpoint of the width of the transfer area is 30% or more and 70% or less of the average value of the sag amount Z1 at the boundary between the base area and the transfer area and the sag amount Z2 at the boundary between the transfer area and the defocus area.

[0010] A fifth aspect of the present invention is The spectacle lens is a myopia progression inhibiting lens, according to any one of the first to fourth aspects.

[0011] A sixth aspect of the present invention is a method for manufacturing a semiconductor device comprising: a step of designing a base region that causes a light beam incident from a surface on the object side to exit from a surface on the eyeball side and converge at a predetermined position A on the retina via the eyeball; a step of designing a plurality of defocus areas each having a property of converging a light beam to a position B closer to the object side than the position A, or to a position C on the opposite side of the position B as viewed from the position A; designing a transfer region provided at a boundary between the base region and the defocus region, the transfer region grading a change in curvature between the base region and the defocus region; The present invention relates to a method for designing a spectacle lens, comprising: [Effects of the Invention]

[0012] According to one embodiment of the present invention, it is possible to provide a spectacle lens that can improve contrast while applying DIMS. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a plan view of the object side surface of a spectacle lens 100 according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the periphery of the defocus region 20 in the eyeglass lens 100 according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a graph showing the relationship between the MTF and the width t of the transfer region 30 at the respective light-condensing positions of the base region 10 and the defocus region 20 (including the transfer region 30) of the eyeglass lens 100 according to the first embodiment of the present invention. [Figure 4] FIG. 4 is an enlarged cross-sectional view of the periphery of the defocus region 20 of the eyeglass lens 100 according to the second embodiment of the present invention. [Figure 5] Figure 5(a) is a diagram showing the change in the amount of sag around the defocus area 20 of sample 1 according to an embodiment of the present invention, and Figure 5(b) is a diagram showing the change in the amount of sag around the defocus area 20 of sample 2 according to an embodiment of the present invention. [Figure 6] FIG. 6 is an enlarged cross-sectional view of the periphery of the defocus region 20 in the DIMS according to the reference example. DETAILED DESCRIPTION OF THE INVENTION

[0014] <Insights gained by the inventor> First, the findings of the inventors will be described. Fig. 6 is an enlarged cross-sectional view of the periphery of the defocus region 20 in a DIMS according to a reference example. For simplicity, Fig. 6 shows the base region 10 as a flat surface, with the curvature of the base region 10 subtracted.

[0015] In the DIMS shown in FIG. 6, the base region 10 and the defocus region 20 are designed with only geometrical optical phenomena in mind, and therefore the curvature changes discontinuously at the boundary 40 between the base region 10 and the defocus region 20. This causes wave-optical phenomena (such as diffraction) at the boundary 40, resulting in a problem of reduced spot quality. Furthermore, when a functional film such as a hard coat film is formed on a lens substrate by coating or other methods, a liquid puddle of the film material may form near the boundary 40, potentially resulting in shape errors during processing. In this specification, the term "spot" refers to a light beam at an arbitrary position (focus position), and the term "spot quality" refers to, for example, the level of contrast at the focus position.

[0016] The inventors of the present invention have conducted extensive research into the above-mentioned problems, taking into consideration wave optics phenomena, and have found that by providing a region (hereinafter referred to as transfer region 30) in boundary portion 40 that smooths the change in curvature between base region 10 and defocus region 20, it is possible to improve spot quality while improving ease of processing.

[0017] [Details of the embodiment of the present invention] Next, an embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0018] It should be noted that any content not described in this specification is deemed to be fully described in Patent Document 1. Any content not described in Patent Document 1 (particularly content relating to the manufacturing method) is deemed to be fully described in WO2020 / 004551. If there is a discrepancy between the content of Patent Document 1 and the content of the publication, the content of the publication takes precedence.

[0019] The spectacle lenses mentioned in this specification have an object-side surface and an eyeball-side surface. The "object-side surface" is the surface that is located on the object side when a wearer wears spectacles equipped with the spectacle lens, and the "eyeball-side surface" is the opposite, i.e., the surface that is located on the eyeball side when a wearer wears spectacles equipped with the spectacle lens. This relationship also applies to the lens substrate that forms the basis of the spectacle lens. In other words, the lens substrate also has an object-side surface and an eyeball-side surface.

[0020] <First embodiment of the present invention> (1) Eyeglass lenses FIG. 1 is a plan view of the object-side surface of a spectacle lens 100 according to the present embodiment. The spectacle lens 100 of the present embodiment includes a base region 10, multiple defocus regions 20, and multiple transfer regions 30. In the present embodiment, the base region 10 is a refractive region designed to reflect the prescribed refractive power of the wearer, and is designed to cause a light beam incident from the object-side surface to exit from the eyeball-side surface and converge via the wearer's eyeball at a predetermined position (position A) on the retina. In the present embodiment, the defocus region 20 is configured to cause a light beam incident from the object-side surface to exit from the eyeball-side surface and converge via the wearer's eyeball at a position (position B) closer to the object side than position A, or at a position (position C) opposite position B as viewed from position A. In the present embodiment, the transfer region 30 is provided at the boundary between the base region 10 and the defocus region 20, and is disposed so as to surround each of the defocus regions 20.

[0021] The base region 10 is a portion having a shape that can realize the prescribed refractive power of the wearer, and corresponds to the first refractive region of Patent Document 1. The surface shape of the base region 10 is not particularly limited. The base region 10 may be spherical, aspherical, toric, or a mixture of these. In this embodiment, the case where the base region 10 has a spherical shape is exemplified.

[0022] The defocus region 20 is a region in which at least a portion does not focus light at the light-focusing position of the base region 10. The defocus region 20 is a portion corresponding to the minute convex portion of Patent Document 1. The eyeglass lens 100 of this embodiment is a myopia progression inhibiting lens, similar to the eyeglass lens described in Patent Document 1. As with the minute convex portion of Patent Document 1, the multiple defocus regions 20 of this embodiment may be formed on at least one of the object-side surface or the eyeball-side surface of the eyeglass lens 100. In this embodiment, an example is shown in which multiple defocus regions 20 are provided only on the object-side surface of the eyeglass lens 100.

[0023] The surface shape of the defocus region 20 is not particularly limited. The defocus region 20 may be spherical, aspherical, toric, or a mixture of these shapes. In this embodiment, the case where the defocus region 20 has a spherical shape is exemplified.

[0024] The number of defocus regions 20 included in the eyeglass lens 100 is not particularly limited, but may be, for example, 20 or more and 500 or less.

[0025] The multiple defocus regions 20 are arranged, for example, in an island shape (i.e., spaced apart and not adjacent to each other). The arrangement of the multiple defocus regions 20 is not particularly limited. In this embodiment, as shown in FIG. 1, the multiple defocus regions 20 are arranged independently and discretely so that the centers of the defocus regions 20 are vertices of equilateral triangles (hereinafter also referred to as an equilateral triangle arrangement). Note that the multiple defocus regions 20 may be arranged so that parts of each defocus region are in contact with each other.

[0026] As shown in FIG. 10 of Patent Document 1, a defocus region 20 may be formed in the center of the eyeglass lens 100, or as shown in FIG. 1 of Patent Document 1, a defocus region 20 may not be formed in the center of the eyeglass lens 100. In this embodiment, as shown in FIG. 1, a case where a defocus region 20 is not formed in the center of the eyeglass lens 100 is illustrated. In this specification, the center of the eyeglass lens 100 refers to the lens center (geometric center, optical center, or centering center) of the eyeglass lens 100 and its vicinity. In this embodiment, a case where the line of sight passes through the lens center when a wearer of the eyeglass lens 100 looks straight ahead is illustrated.

[0027] FIG. 2 is an enlarged cross-sectional view of the periphery of the defocus region 20 in the eyeglass lens 100 of this embodiment. Note that in FIG. 2, for simplicity, the curvature of the base region 10 is subtracted and the base region 10 is shown as a plane. As shown in FIG. 2, the transfer region 30 has a predetermined inclination and is configured to make the change in curvature (or inclination) between the base region 10 and the defocus region 20 gentle. This makes the change in curvature gentler than when the transfer region 30 is not provided, and therefore, improvement in spot quality can be expected. In this embodiment, an example is shown in which the transfer region 30 is provided with equal widths on both the inside and outside of the boundary 40 between the base region 10 and the defocus region 20, assuming that the transfer region 30 is not provided.

[0028] 3 is a graph showing the relationship between the MTF (Modulation Transfer Function) and the width t of the transfer region 30 at the respective light-focusing positions of the base region 10 and the defocus region 20 (including the transfer region 30) of the eyeglass lens 100 of this embodiment. The graph in the upper left of FIG. 3 shows the MTF of low frequencies (CPD (Cycles Per Degree) = 4, corresponding to visual acuity of 0.15) at the light-focusing position of the base region 10. The graph in the upper right of FIG. 3 shows the MTF of low frequencies (CPD = 4, corresponding to visual acuity of 0.15) at the light-focusing position of the defocus region 20. The graph in the lower left of FIG. 3 shows the MTF of high frequencies (CPD = 15, corresponding to visual acuity of 0.5) at the light-focusing position of the base region 10. The graph in the lower right of FIG. 3 shows the MTF of high frequencies (CPD = 15, corresponding to visual acuity of 0.5) at the light-focusing position of the defocus region 20. Hereinafter, the spot quality (level of contrast at the light-focusing position) will be evaluated using the MTF value.

[0029] 3, the power of the defocus region 20 (relative power to the base region 10) was set to 3.5D, and the diameter d was set to 1.0 mm. In this specification, the diameter d of the defocus region 20 is calculated from the distance between the boundary 40 between the base region 10 and the defocus region 20 on the assumption that the transfer region 30 is not provided. When determining the diameter d of the defocus region 20 from the actual eyeglass lens 100 product, the boundary 40 can be determined as the intersection of the curvature (approximate curvature) near the center of the defocus region 20 and the curvature of the base region 10.

[0030] As shown in the graphs in the upper and lower left of Figure 3, the MTF at the light-condensing position of the base region 10 tends to improve initially and then decrease as the width t of the transfer region 30 increases. If the width t of the transfer region 30 is too large, the area of ​​the base region 10 is reduced, resulting in a decrease in MTF. In contrast, by controlling the width t of the transfer region 30 within a predetermined range, the effect of improving MTF by gradual changes in curvature exceeds the decrease in MTF due to the reduction in the area of ​​the base region 10, thereby improving MTF.

[0031] 3, the MTF at the light collection position of the defocus region 20 (including the transfer region 30) improves as the width t of the transfer region 30 increases. This is because the area of ​​the region that can be considered as the defocus region 20 increases as the width t of the transfer region 30 increases.

[0032] From the viewpoint of improving the low-frequency MTF, the width t of the transfer region 30 is preferably, for example, 5.0% to 8.5% of the diameter d of the defocus region 20. As shown in the graph in the upper left of FIG. 3, when the width t is less than 5.0% of the diameter d (t<0.05 mm), the MTF increases monotonically as the width t increases. Therefore, from the viewpoint of improving the ease of processing the transfer region 30, it is preferable to set the width t to 5.0% or more of the diameter d. Furthermore, as shown in the graph in the upper left of FIG. 3, when the width t exceeds 8.5% of the diameter d (t>0.085 mm), the MTF may decrease compared to when the transfer region 30 is not provided (t=0 mm) due to the influence of the reduced area of ​​the base region 10. In contrast, by setting the width t to 8.5% or less of the diameter d, the MTF does not decrease compared to when the transfer region 30 is not provided. In other words, it is possible to improve the MTF and processability at the light-focus position of the defocus region 20 without risk.

[0033] From the viewpoint of improving both the low-frequency MTF and the high-frequency MTF, it is preferable that the width t of the transfer region 30 be, for example, 5.0% to 7.0% of the diameter d of the defocus region 20. As shown in the graph at the bottom left of Fig. 3, if the width t exceeds 7.0% of the diameter d (t>0.07 mm), the high-frequency MTF may decrease compared to when the transfer region 30 is not provided.

[0034] 2 illustrates a case where the transfer region 30 has a linear slope (i.e., the sag amount of the transfer region 30 varies linearly), but the slope of the transfer region 30 may also have an R. By adding an R to the slope of the transfer region 30 (making it curved), it is possible to make the change in curvature between the base region 10 and the defocus region 20 more gradual. From the perspective of efficiently improving spot quality, for example, the sag amount Z at the midpoint in the width direction of the transfer region 30 is preferably 30% to 70% of the average value (i.e., (Z1 + Z2) / 2) of the sag amount Z1 at the boundary 41 between the base region 10 and the transfer region 30 and the sag amount Z2 at the boundary 42 between the transfer region 30 and the defocus region 20. In this embodiment, the area where the curvature changes by 100% or more from the curvature of the base region 10 may be defined as the boundary 41, and the area where the curvature changes by 100% or more from the curvature of the defocus region 20 may be defined as the boundary 42.

[0035] In the eyeglass lens 100, it is not necessary to provide transfer regions 30 around all defocus regions 20. From the viewpoint of efficiently improving spot quality, for example, when the object-side surface of the eyeglass lens 100 is viewed in plan, it is preferable that transfer regions 30 be provided around 70% or more (more preferably 80% or more, and even more preferably 90% or more) of the defocus regions 20 that exist within a circumference with a diameter of 20 mm from the lens center.

[0036] Various commonly used lens substrates can be used as the lens substrate constituting the spectacle lens 100. The lens substrate may be, for example, a plastic lens substrate or a glass lens substrate. The glass lens substrate may be, for example, a lens substrate made of inorganic glass. A plastic lens substrate is preferred as the lens substrate from the viewpoint of being lightweight and shatter-resistant. Examples of plastic lens substrates include styrene resins such as (meth)acrylic resins, polycarbonate resins, allyl resins, allyl carbonate resins such as diethylene glycol bisallyl carbonate resin (CR-39), vinyl resins, polyester resins, polyether resins, urethane resins obtained by reacting an isocyanate compound with a hydroxy compound such as diethylene glycol, thiourethane resins obtained by reacting an isocyanate compound with a polythiol compound, and cured products (generally referred to as transparent resins) obtained by curing a curable composition containing a (thio)epoxy compound having one or more disulfide bonds in the molecule. The curable composition may also be referred to as a polymerizable composition. The lens substrate may be undyed (colorless lenses) or dyed (dyed lenses). The thickness and diameter of the lens substrate are not particularly limited, but for example, the thickness (center thickness) may be approximately 1 to 30 mm, and the diameter may be approximately 50 to 100 mm. The refractive index of the lens substrate may be, for example, approximately 1.60 to 1.75. However, the refractive index of the lens substrate is not limited to this range, and may be within this range or may deviate above or below this range. In this specification, the refractive index refers to the refractive index for light with a wavelength of 500 nm.

[0037] A hard coat film containing a resin may be formed on at least one major surface of the lens substrate constituting the eyeglass lens 100. In this case, at least a portion of the slope of the transfer region 30 may be formed by the hard coat film. However, from the viewpoint of improving the processing accuracy of the transfer region 30, it is preferable that at least a portion of the transfer region 30 be configured to gradually change the curvature between the base region 10 and the defocus region 20 by changing the sag amount of the lens substrate. If the slope of the transfer region 30 is formed using only a hard coat film, liquid pools and the like are likely to occur at the boundary portion 40, making it difficult to control the width t of the transfer region 30 within a predetermined range. In contrast, if at least a portion of the slope of the transfer region 30 is formed in advance using the lens substrate, even if a hard coat film is formed thereon, the occurrence of liquid pools and the like is suppressed, making it easier to control the width t of the transfer region 30 within a predetermined range. In other words, the slope of the transfer region 30 can be accurately formed using the lens substrate and the hard coat film.

[0038] (2) Design method for eyeglass lenses The present invention can also be applied to a method for designing a spectacle lens 100. The method for designing a spectacle lens 100 of this embodiment includes the steps of: designing a base region 10 that causes a light beam incident on the object-side surface to exit from the eyeball-side surface and converge at a predetermined position (position A) on the retina via the eyeball; designing a plurality of defocus regions 20 that have the property of converging the light beam at a position (position B) closer to the object side than position A or at a position (position C) opposite position B as viewed from position A; and designing a transfer region 30 that is provided at a boundary 40 between the base region 10 and the defocus region 20 and that smooths the change in curvature between the base region 10 and the defocus region 20. Details of the base region 10, defocus region 20, and transfer region 30 designed in each step will be omitted because they overlap with the description in (1) Spectacle Lens above.

[0039] <Second embodiment of the present invention> Next, a second embodiment of the present invention will be described, focusing on the differences from the first embodiment. Elements that are substantially the same as those described in the first embodiment will be assigned the same reference numerals, and descriptions thereof will be omitted.

[0040] The present invention is applicable not only to myopia progression inhibiting lenses but also to hyperopia progression inhibiting lenses. FIG. 4 is an enlarged cross-sectional view of the periphery of the defocus region 20 of a spectacle lens 100 according to a second embodiment of the present invention. For simplicity, FIG. 4 shows the base region 10 as a flat surface, with the curvature of the base region 10 subtracted. As shown in FIG. 4, the defocus region 20 of this embodiment is a minute recess. As in the first embodiment described above, in this embodiment, a transfer region 30 is provided around the defocus region 20, and the transfer region 30 is configured to make the change in curvature between the base region 10 and the defocus region 20 gentle. This allows for improved spot quality, as in the first embodiment.

[0041] For the same reasons as in the first embodiment, the width t of the transfer region 30 in this embodiment is preferably 5.0% to 8.5% of the diameter d of the defocus region 20. Also, for the same reasons as in the first embodiment, the sag Z at the midpoint in the width direction of the transfer region 30 in this embodiment is preferably 30% to 70% of the average value (i.e., (Z1+Z2) / 2) of the sag Z1 at the boundary 41 between the base region 10 and the transfer region 30 and the sag Z2 at the boundary 42 between the transfer region 30 and the defocus region 20. Also, for the same reasons as in the first embodiment, at least a portion of the transfer region 30 in this embodiment is preferably configured to moderate the change in curvature between the base region 10 and the defocus region 20 due to a change in the sag of the lens substrate.

[0042] <Other Embodiments of the Present Invention> Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the present invention.

[0043] For example, in the above-described embodiment, at least a portion of the transfer region 30 is configured to gradually change the curvature between the base region 10 and the defocus region 20 by changing the sag amount of the lens substrate. However, the slope of the transfer region 30 may be formed only by a hard coat film without changing the sag amount of the lens substrate. In this case, there is no need to change the mold for forming the lens substrate from that of the reference example. However, from the perspective of improving the processing accuracy of the transfer region 30, it is preferable to form at least a portion of the slope of the transfer region 30 by the lens substrate, as in the above-described embodiment. [Example]

[0044] Next, examples of the present invention will be described. These examples are merely examples of the present invention, and the present invention is not limited to these examples.

[0045] Sample 1 of the eyeglass lens 100 was designed under the following conditions. The base region 10 and the defocus region 20 were spherical, and the slope of the transfer region 30 was linear. Figure 5(a) shows the change in the amount of sag around the defocus region 20 of Sample 1. Lens substrate refractive index: 1.6D Base area 10 degrees: 1D Defocus area 20 power (relative to base area 10 power): 3.5D Diameter d of defocus area 20: 1.0 mm Width of transfer area 30: 0.08 mm

[0046] Sample 2 of the spectacle lens 100 was designed in the same manner as Sample 1, except that the width t of the transfer region 30 was set to 0.065 mm.

[0047] Sample 3 of the eyeglass lens 100 was designed in the same way as Sample 1, except that the width t of the transfer region 30 was set to 0.04 mm. Figure 5(b) shows the change in the amount of sag around the defocus region 20 of Sample 3.

[0048] Sample 4 of the spectacle lens 100 was designed in the same way as sample 1, except that the transfer region 30 was not provided.

[0049] The MTF was calculated for each of the light-condensing positions of the base region 10 and the defocus region 20 for Samples 1 to 4. The MTF for low frequencies (CPD=4, equivalent to 0.15 visual acuity) at the light-condensing position of the base region 10 was 73.1% for Sample 1, 73.2% for Sample 2, 73.2% for Sample 3, and 73.1% for Sample 4. The MTF for high frequencies (CPD=15, equivalent to 0.5 visual acuity) at the light-condensing position of the base region 10 was 20.2% for Sample 1, 20.3% for Sample 2, 20.4% for Sample 3, and 20.3% for Sample 4. The MTF for low frequencies (CPD=4, equivalent to 0.15 visual acuity) at the light-condensing position of the defocus region 20 was 50.5% for Sample 1, 49.6% for Sample 2, 49.0% for Sample 3, and 48.3% for Sample 4. Furthermore, the MTF for high frequencies (CPD=15, equivalent to 0.5 visual acuity) at the light-condensing position of the defocus region 20 was 18.7% for sample 1, 18.5% for sample 2, 18.3% for sample 3, and 18.1% for sample 4. In other words, it was confirmed that the addition of the transfer region 30 resulted in almost no decrease in MTF at the light-condensing position of the base region 10 (except for a 0.1% drop in high frequencies in sample 1), and an improvement in MTF at the light-condensing position of the defocus region 20 was obtained.

[0050] From the above, it was confirmed that spot quality can be improved by providing transfer region 30. When a hard coat film is formed on a lens substrate, the width t of transfer region 30 may become larger than the design value of the lens substrate due to the hard coat film, so it may be preferable to design width t of transfer region 30 to be smaller (for example, less than 5.0% of diameter d of defocus region 20), as in sample 3. [Explanation of symbols]

[0051] 10 Base Area 20 Defocus Area 30 Transfer Region 40 Boundary (between base region 10 and defocus region 20) 41 Boundary (between base region 10 and transfer region 30) 42 Boundary (between transfer region 30 and defocus region 20) 100 eyeglass lenses

Claims

1. a base region that causes a light beam incident on the object-side surface to exit from the eyeball-side surface and converge at a predetermined position A on the retina via the eyeball; a plurality of defocus areas each having a property of converging a light beam to a position B closer to the object side than the position A, or to a position C on the opposite side of the position B as viewed from the position A; a transfer region provided at a boundary between the base region and the defocus region, which reduces the change in curvature between the base region and the defocus region; the plurality of defocus regions are discretely arranged without being adjacent to each other, the width of the transfer region is 5.0% or more and 8.5% or less of the diameter of the defocus region, An eyeglass lens, wherein at least a portion of the transfer region is configured to provide a gradual change in curvature between the base region and the defocus region by varying the amount of sag of the lens substrate.

2. The eyeglass lens of claim 1, wherein the defocus area has a spherical shape, an aspherical shape, a toric shape, or a shape that is a mixture of these.

3. The eyeglass lens of claim 1, wherein the defocus area is spherical.

4. 4. The eyeglass lens according to claim 1, wherein a sag amount Z at the midpoint of the transfer region in the width direction is 30% or more and 70% or less of an average value of a sag amount Z1 of the lens substrate at the boundary between the base region and the transfer region and a sag amount Z2 of the lens substrate at the boundary between the transfer region and the defocus region.

5. The spectacle lens according to claim 1 , wherein the spectacle lens is a myopia progression inhibiting lens.

6. a step of designing a base region that causes a light beam incident from a surface on the object side to exit from a surface on the eyeball side and converge at a predetermined position A on the retina via the eyeball; a step of designing a plurality of defocus regions each having a property of converging a light beam to a position B closer to the object side than the position A, or to a position C on the opposite side of the position B as viewed from the position A; and designing a transfer region provided at a boundary between the base region and the defocus region, the transfer region grading a change in curvature between the base region and the defocus region; the plurality of defocus regions are discretely arranged without being adjacent to each other, the width of the transfer region is 5.0% or more and 8.5% or less of the diameter of the defocus region, A method for designing a spectacle lens, wherein at least a portion of the transfer region is configured to gradually change the curvature between the base region and the defocus region by changing the amount of sag of the lens substrate.

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