Eyeglass lenses and their design methods

Abstract

To provide a technique that can flexibly change a focal position according to a position on a spectacle lens and brought to a wearer by defocus areas.SOLUTION: There is provided a technique such that: a spectacle lens comprises a base area that causes a light beam incident on a surface on an object side to emit from a surface on an eyeball side and converge on the retina through the eyeball, and a plurality of defocus areas that are surrounded by the base area, the defocus areas having properties in which the light beam passing through at least part of the defocus areas makes incident on the retina as divergent light; the defocus areas include a defocus area a provided at a predetermined position A on the spectacle lens and a defocus area b provided at a predetermined position B; with reference to a base surface constituted by the base area, when the normal direction of the base surface being the direction directed to the outside of the lens is a positive sag value, and the direction directed to the inside of the lens is a negative sag value, the sag value of the three-dimensional shape of the defocus area b is a value obtained by increasing the sag value of the three-dimensional shape of the defocus area a.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to spectacle lenses and a method for designing the same.

Background Art

[0002] As a spectacle lens for suppressing the progression of refractive errors such as myopia, there is one in which island regions having a refractive power plus more than a plurality of prescribed refractive powers are formed on the lens (see, for example, Patent Document 1). Hereinafter, this island region is referred to as a defocus region.

[0003] According to the spectacle lens having this configuration, among the light beams incident from the object side surface and exiting from the eyeball side surface, the light beams passing through other than the defocus region are focused on the wearer's retina, but the light beams passing through the defocus region are focused at a position in front of the retina, thereby suppressing the progression of myopia.

[0004] In this specification, the front direction where an object to be visually recognized exists in the optical axis direction is referred to as the front side, and the opposite direction of the front side, that is, the rearward direction in the optical axis direction, that is, the depth direction from the spectacle lens toward the eyeball is referred to as the back side.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Depending on the position of the defocus area on the spectacle lens from which the light beam is incident and exits, the best focal position (Best Focal) that should ultimately be provided to the wearer is different. The reasons are as follows. The best focal position varies depending on the degree of myopia progression, the state of the choroid, the angle of incidence during wearing, the aberration of the eye (field curvature), and the curvature of the retina, which are different for different wearers. The degree of this variation generally increases as the distance from the lens center increases. That is, the defocus power to be given to the wearer varies depending on the wearer or the position of the lens. The best focal position is also simply referred to as the "focal position".

[0007] The "focal position" in this specification refers to the focal point position. However, the focal position has a slightly different meaning from the geometric focal point determined by the shape of the defocus area (for example, the spherical shape with a radius of curvature R). The focal position is the best position of the wave optical contrast considering the frequency characteristics of the eye (for example, having a peak at low frequencies).

[0008] Generally, the focal position varies depending on the concept and application, such as the position where the contrast of the target spatial frequency is the highest, the position where the energy is the highest, and the position where the variation of the light rays is the smallest. Therefore, it is preferable to flexibly handle the defocus area that provides the focal position. The inventor adopted the above-mentioned definition regarding the focal position, focusing on the fact that the retina is a collection of cells that respond to specific spatial frequencies.

[0009] An embodiment of the present invention aims to provide a technique that can flexibly change the focal position that the defocus area should provide to the wearer according to the position on the spectacle lens. In particular, it aims to provide a technique that can flexibly change the focal position while keeping the surface shapes of the defocus areas equal to each other.

Means for Solving the Problem

[0010] The first aspect of the present invention is A base region that emits a light beam incident from the surface on the object side from the surface on the eyeball side and converges it onto the retina through the eyeball, A plurality of defocus regions that are defocus regions surrounded by the base region, and a light beam passing through at least a part of the defocus region has the property of entering the retina as a divergent light beam, Comprising The defocus region includes a defocus region a provided at a predetermined position A on the spectacle lens and a defocus region b provided at a predetermined position B, When, with reference to the base surface constituted by the base region, the direction normal to the base surface and directed outside the lens is defined as a positive sag value and the direction directed inside the lens is defined as a negative sag value, the sag value of the three-dimensional shape of the defocus region b is a value obtained by increasing the sag value of the three-dimensional shape of the defocus region a. It is a spectacle lens.

[0011] A second aspect of the present invention is The spectacle lens according to the first aspect, wherein at least the central portions of the defocus region a and the defocus region b have a curved surface shape protruding toward the outside of the lens.

[0012] A third aspect of the present invention is The spectacle lens according to the second aspect, wherein the radius of curvature of the central portion of the defocus region a and the radius of curvature of the central portion of the defocus region b are equal.

[0013] A fourth aspect of the present invention is The spectacle lens according to any one of the first to third aspects, wherein the increase amount of the sag value in the three-dimensional shape is constant.

[0014] A fifth aspect of the present invention is The spectacle lens according to any one of the first to fourth aspects, wherein the bottom area of the defocus region a and the bottom area of the defocus region b are equal.

[0015] A sixth aspect of the present invention is The predetermined position A is a position near the periphery of the lens, and the predetermined position B is a position near the center of the lens, or In the spectacle lens according to any one of the first to fifth aspects, the predetermined position A is a position closer to the center of the lens, and the predetermined position B is a position closer to the periphery of the lens.

[0016] A seventh aspect of the present invention is In the spectacle lens according to any one of the first to sixth aspects, the sag value in the three-dimensional shape of the defocus area a is negative near the base area.

[0017] An eighth aspect of the present invention is The spectacle lens according to any one of the first to seventh aspects, wherein the defocus regions T are a set of defocus regions that account for 80% or more of all defocus regions, the defocus regions T including the defocus region b and the defocus region a have the same radius of curvature at their central locations, and the number of defocus regions T that have the same sag value as the defocus region a is 10 to 90%, and the number of defocus regions T that have the same sag value as the defocus region b is 10 to 90%. Preferably, the set T of defocus regions is set to 90% or more, or 95% or more of the total number of defocus regions.

[0018] A ninth aspect of the present invention is a method for manufacturing a semiconductor device comprising: At least central portions of the defocus area a and the defocus area b have a curved surface shape that protrudes toward the outside of the lens, The amount of increase in the sag value is constant, The radius of curvature of the center of the defocus area a is equal to the radius of curvature of the center of the defocus area b, The bottom area of the defocus area a is equal to the bottom area of the defocus area b, The predetermined position A is a position near the periphery of the lens, and the predetermined position B is a position near the center of the lens, or The predetermined position A is a position closer to the center of the lens, and the predetermined position B is a position closer to the periphery of the lens, A set T of defocus regions, which contains more than 80% of the total number of defocus regions, and includes the defocus region a and the defocus region b. In the defocus region T, the refractive power at the center of each defocus region is equal. Among the defocus regions in the defocus region T, the number of defocus regions with the same sag value as the defocus region a is 10% - 90%, and the number of defocus regions with the same sag value as the defocus region b is 10% - 90%. The spectacle lens according to the first aspect. Preferably, the set T of defocus regions is composed of 90% or more, more preferably 95% or more of the total number of defocus regions.

[0019] The tenth aspect of the present invention is The spectacle lens according to any one of the first to ninth aspects, wherein the spectacle lens is a myopia progression-inhibiting lens.

[0020] The eleventh aspect of the present invention is A base region that emits a light beam incident from the object side surface from the eyeball side surface and converges it onto the retina through the eyeball, and A plurality of defocus regions that are defocus regions surrounded by the base region, and at least a part of the light beam passing through the defocus regions has the property of entering the retina as divergent light. A method for designing a spectacle lens, comprising Based on the base surface formed by the base region, when the direction normal to the base surface and facing outward of the lens is defined as a positive sag value and the direction facing inward of the lens is defined as a negative sag value, By increasing the sag value of the three-dimensional shape of the defocus region to raise the defocus region with respect to the base surface, or By decreasing the sag value of the three-dimensional shape of the defocus region to sink the defocus region with respect to the base surface, A method for designing a spectacle lens that changes the focus position according to the position on the spectacle lens where the defocus region is provided for the wearer.

[0021] The twelfth aspect of the present invention is changing the focus position by changing a value obtained by dividing, by the bottom area of the defocus region, a value obtained by subtracting a volume of a portion between the defocus region and the base surface and having a negative sag value from a volume of a portion between the defocus region and the base surface and having a positive sag value, which is the design method of the spectacle lens according to the eleventh aspect.

[0022] Other aspects of the present invention that can be combined with the above aspects are as follows.

[0023] The sag values of the entire three-dimensional shape of the defocus region a at the predetermined position A and the sag value of the entire three-dimensional shape of the defocus region b at the predetermined position may both be positive or both negative. The sag values at the position of the center (or centroid) in plan view may both be positive or both negative.

[0024] At least the central portion of the three-dimensional shape of the defocus region a and at least the central portion of the three-dimensional shape of the defocus region b may both be spherical.

[0025] The sag value of the entire three-dimensional shape of the defocus region a may be positive.

[0026] When it is assumed that the three-dimensional shape of the defocus region a and the three-dimensional shape of the defocus region b are aligned at the center (or centroid) in plan view and the base surface and overlapped, it is preferable that the three-dimensional shape of the defocus region b exists in the +Z direction as viewed from the three-dimensional shape of the defocus region a. In the above assumption, it is preferable that the three-dimensional shape of the defocus region a does not protrude from the three-dimensional shape of the defocus region b. Preferably, when the above overlap is assumed, the two shapes do not contact each other.

[0027] The above sag value relationship may be satisfied in a lens substrate on which defocus regions a and b are formed. The above sag value relationship may be satisfied in a lens substrate on which a hard coat film is formed, or in a lens substrate on which an antireflection film is further formed. When a hard coat film is formed, the defocus regions a and b may be realized by the hard coat film on a lens substrate on which defocus regions a and b are not formed.

[0028] The predetermined position A may be a position closer to the nose, and the predetermined position B may be a position closer to the ear. Conversely, the predetermined position A may be a position closer to the ear, and the predetermined position B may be a position closer to the nose. In either case, the sag value near the base region in the three-dimensional shape of the defocus region a at the predetermined position A may be negative.

[0029] Approximately circular defocus regions may be arranged in an island pattern (i.e., spaced apart and not adjacent to each other) around the center of the eyeglass lens at equal intervals in the circumferential and radial directions. One example of the arrangement of the defocus regions in a planar view is an example in which the defocus regions are independently and discretely arranged so that the centers of the defocus regions are at the vertices of an equilateral triangle (the centers of the defocus regions are arranged at the vertices of a honeycomb structure). This arrangement is also called a "hexagonal arrangement." This example is mainly described in this specification.

[0030] It is preferable that at least half of the multiple defocus regions (all defocus regions) are arranged at the same period in plan view. An example of a pattern with the same period is the hexagonal arrangement described above. The period may be in the circumferential direction and / or the radial direction. It is preferable that the period be 80% or more, more preferably 90% or more, and even more preferably 95% or more.

[0031] When the sag value (e.g., the maximum sag value) of the three-dimensional shape of the defocus area a is the smallest among all the defocus areas, it is preferable that in 80% or more of the defocus areas in all the defocus areas, the relationship that "the sag value of the three-dimensional shape of the defocus area b is a value obtained by increasing the sag value of the three-dimensional shape of the defocus area a" is satisfied. This means that there are not only the defocus area b, but also defocus areas c, d, e... (all having a larger sag value than the defocus area a and having a different amount of increase in the sag value from the defocus area b) that satisfy the above relationship.

[0032] The diameter of the defocus area in plan view is preferably about 0.6 to 2.0 mm. The sag amount (protrusion height, protrusion amount) of the defocus area is about 0.1 to 10 μm, preferably 0.4 to 2.0 μm. The radius of curvature of the convex area is spherical with a radius of 50 to 250 mm, preferably about 86 mm.

[0033] It is preferable that the minimum value of the defocus power provided by the defocus area on the spectacle lens is within the range of 0.50 to 4.50 D, and the maximum value is within the range of 3.00 to 10.00 D. The difference between the maximum value and the minimum value is preferably within the range of 1.00 to 5.00 D.

[0034] The film thickness of the film provided on the lens substrate may be in the range of, for example, 0.1 to 100 μm (preferably 0.5 to 5.0 μm, more preferably 1.0 to 3.0 μm).

[0035] A base area that makes the light beam incident from the object side surface exit from the eyeball side surface and converge on the retina through the eyeball, A plurality of defocus areas that are defocus areas surrounded by the base area and have the property that the light beam passing through at least a part of the defocus area enters the retina as divergent light, A spectacle lens design system comprising: Based on the base surface constituted by the base area, when the direction normal to the base surface and facing outward of the lens is defined as a positive sag value and the direction facing inward of the lens is defined as a negative sag value, By increasing the sag value of the three-dimensional shape of the defocus area to raise the defocus area with respect to the base surface, or by decreasing the sag value of the three-dimensional shape of the defocus area to sink the defocus area with respect to the base surface, An eyeglass lens design system including an arithmetic unit that changes the focus position according to the position on the eyeglass lens where the defocus area is provided for the wearer.

[0036] A base area that emits a light beam incident from the object side surface from the eyeball side surface and converges it on the retina through the eyeball, and A defocus area surrounded by the base area, the defocus area having a property that a light beam passing through at least a part of the defocus area enters the retina as divergent light, and a plurality of defocus areas, An eyeglass lens design program including: Based on the base surface constituted by the base area, when the direction normal to the base surface and directed outside the lens is defined as a positive sag value and the direction directed inside the lens is defined as a negative sag value, By increasing the sag value of the three-dimensional shape of the defocus area to raise the defocus area with respect to the base surface, or by decreasing the sag value of the three-dimensional shape of the defocus area to sink the defocus area with respect to the base surface, An eyeglass lens design program that causes a computer device to function as an arithmetic unit that changes the focus position according to the position on the eyeglass lens where the defocus area is provided for the wearer.

Advantages of the Invention

[0037] According to an embodiment of the present invention, it is possible to provide a technique for flexibly changing the focus position that the defocus area should bring to the wearer according to the position on the eyeglass lens. In particular, it is possible to provide a technique for flexibly changing the focus position while the surface shapes of the defocus areas are equal to each other.

Brief Description of the Drawings

[0038]

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[0039] Hereinafter, embodiments of the present invention will be described. The following explanation based on the drawings is an example, and the present invention is not limited to the exemplified embodiments. Contents not described in this specification are assumed to be fully described in Patent Document 1, and contents not described in Patent Document 1 (particularly contents relating to the manufacturing method) are assumed to be fully described in WO2020 / 004551. If there is a discrepancy between the contents of Patent Document 1 and the contents of the publication, the contents of the publication shall take precedence.

[0040] 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.

[0041] In this specification, the horizontal direction with the glasses lenses worn is defined as the X direction, the vertical (up and down) direction as the Y direction, and the direction perpendicular to the X and Y directions in the thickness direction of the glasses lenses as the Z direction. The right side towards the wearer is defined as the +X direction, the left side as the -X direction, the upper side as the +Y direction, the lower side as the -Y direction, the object side direction as the +Z direction, and the opposite direction (the back side direction) as the -Z direction.

[0042] In this specification, "~" indicates a value greater than or equal to a predetermined value and less than or equal to a predetermined value. Hereinafter, reference numerals will be attached, but only to the first appearance of an item, and will be omitted thereafter.

[0043] <Glasses lenses> The glasses lenses according to one aspect of the present invention include a base region that emits a light beam incident from the object side surface from the eyeball side surface and converges it onto the retina through the eyeball, and a defocus region surrounded by the base region, the defocus region having a plurality of defocus regions through which at least a part of the light beam passing through has the property of entering the retina as divergent light.

[0044] The base region is a portion having a shape capable of realizing the refractive power of the wearer's prescription from the viewpoint of geometric optics, and corresponds to the first refractive region of Patent Document 1.

[0045] The defocus region is a region in which at least a part of the region does not converge to the converging position by the base region from the viewpoint of geometric optics. The defocus region corresponds to the minute convex portions of Patent Document 1. The glasses lenses according to one aspect of the present invention are myopia progression-inhibiting lenses, similar to the glasses lenses described in Patent Document 1. Similar to the minute convex portions of Patent Document 1, the plurality of defocus regions according to one aspect of the present invention may be formed on at least either the object side surface or the eyeball side surface of the glasses lenses. In this specification, the case where a plurality of defocus regions are provided only on the object side surface of the glasses lenses will be mainly exemplified. Hereinafter, unless otherwise specified, the defocus region will be exemplified as having a curved surface shape protruding towards the outside of the lens.

[0046] As described in FIG. 10 of Patent Document 1, a defocus region may be formed at the central portion of the spectacle lens, or as described in FIG. 1 of Patent Document 1, a defocus region may not be formed at the central portion of the spectacle lens. In one aspect of the present invention, a case where a defocus region is not formed at the central portion of the spectacle lens is exemplified.

[0047] The "central portion of the spectacle lens" refers to the vicinity of the lens center. In this specification, the case of the centering center and its vicinity is exemplified. The centering center is also referred to as the lens center. In this specification, the case where the lens center passes when the wearer views straight ahead is exemplified.

[0048] The defocus region in the spectacle lens of one aspect of the present invention includes a defocus region a provided at a predetermined position A on the spectacle lens and a defocus region b provided at a predetermined position B.

[0049] Based on the base surface constituted by the base region, the direction in the normal direction of the base surface and toward the outside of the lens is set as a positive sag value, and the direction toward the inside of the lens is set as a negative sag value.

[0050] Strictly speaking, the normal direction of the base surface is different in each defocus region, but the difference is a slight difference. Therefore, in this specification, the normal direction is treated as the Z direction. That is, the direction toward the outside of the lens (in this example, the direction from the surface on the eyeball side to the surface on the object side) is treated as the +Z direction, and the direction toward the inside of the lens (in this example, the reverse direction) is treated as the -Z direction. In this specification, a plan view is a view when looking from the +Z direction to the -Z direction.

[0051] The "base surface" is one main surface of the spectacle lens (in this example, the surface on the object side) when it is assumed that there is no defocus region.

[0052] The sag value of the three-dimensional shape of the defocus area b of the spectacle lens according to one aspect of the present invention is a value obtained by increasing the sag value of the three-dimensional shape of the defocus area a (bulging, raising). In other words, the sag value of the three-dimensional shape of the defocus area a is a value obtained by decreasing the sag value of the three-dimensional shape of the defocus area b (sinking, digging down).

[0053] FIG. 1 is a schematic (X-Z) cross-sectional view showing a state where the sag value of the three-dimensional shape of the defocus area (FIG. 1(a)) is increased, the defocus area is raised with respect to the base surface, and the three-dimensional shape of another defocus area (FIG. 1(b)) is set. FIG. 1(c) is an explanatory cross-sectional view when the centers in plan view of both three-dimensional shapes are aligned on the base surface to show the difference in the sag values of both three-dimensional shapes. The solid line indicates the three-dimensional shape of the portion where the sag value is increased. The broken line is the base portion 3 newly formed due to the raising of the defocus area 2 with respect to the base surface 1s constituted by the base area 1. The long broken line in FIG. 1(c) indicates the three-dimensional shape of the defocus area in FIG. 1(a), and the solid line in FIG. 1(c) indicates the three-dimensional shape of the defocus area in FIG. 1(b). FIG. 2 is a schematic (X-Z) cross-sectional view showing a state where the sag value of the three-dimensional shape of the defocus area (FIG. 2(a)) is decreased, the defocus area is sunk with respect to the base surface, and the three-dimensional shape of another defocus area (FIG. 2(b)) is set. FIG. 2(c) is an explanatory cross-sectional view when the centers in plan view of both three-dimensional shapes are aligned on the base surface to show the difference in the sag values of both three-dimensional shapes. The dotted line indicates the base surface. The broken line is the concave portion 4 newly formed between the base area and the defocus area due to the subsidence of the defocus area. The long broken line in FIG. 2(c) indicates the three-dimensional shape of the defocus area in FIG. 2(b), and the solid line in FIG. 2(c) indicates the three-dimensional shape of the defocus area in FIG. 2(a). Note that the above description of FIG. 2 relates to the change from (a) to (b). On the other hand, the change from (b) to (a) is also allowed. In that case, it can be said that the sag value of the three-dimensional shape of the defocus area in (b) is increased, the defocus area is raised with respect to the base surface, and the three-dimensional shape of another defocus area is set.

[0054] The statement in this specification that "the sag value of the three-dimensional shape of the defocus region b is a value obtained by increasing the sag value of the three-dimensional shape of the defocus region a" means, as shown in FIGS. 1(c) and 2(c), that the three-dimensional shape of the defocus region a before the increase in the sag value is displaced in the +Z direction.

[0055] For example, the sag value at a location b1 (e.g., the vertex of the convex region) in the defocus region b is positively larger than the sag value at a location a1 (e.g., the vertex of the convex region) in the defocus region a. Also, both sag values may be positive. However, the boundary with the base region may have a sag value of zero. Therefore, the three-dimensional shape referred to here means the shape inside the boundary with the base region.

[0056] When adopting the vertex of the convex region, the above sag value relationship may hold for the entire central location including the vertex of the convex region (FIGS. 1(c) and 2(c)). In some cases, the same sag value relationship also holds at the outer edge of the convex region (FIG. 2(c)). Instead of the vertex of the convex region, the above sag value relationship may hold at the location of the center (or centroid) in plan view.

[0057] In other words, the above sag value relationship can also be expressed as follows. Assuming that the three-dimensional shape of the defocus region a and the three-dimensional shape of the defocus region b are aligned and superimposed at the center (or centroid) in plan view and the base plane as shown in FIGS. 1(c) and 2(c), when viewed from the three-dimensional shape of the defocus region a, the three-dimensional shape of the defocus region b exists in the +Z direction. In the above assumption (FIGS. 1(c) and 2(c)), even if the three-dimensional shape of the defocus region a could be in contact with the three-dimensional shape of the defocus region b (e.g., contact between the outermost edges of the defocus regions), it does not protrude from the three-dimensional shape. Preferably, when the above superimposition is assumed, the two shapes do not contact.

[0058] The relationship of the above sag values may be satisfied in a lens substrate in which defocus regions a and b are formed. The relationship of the above sag values may be satisfied in a case where a hard coat film is formed on the lens substrate, or may be satisfied in a case where it is formed on a hard coat film of an antireflection film. When forming the hard coat film, the defocus regions a and b may be realized by the hard coat film with respect to a lens substrate in which the defocus regions a and b are not formed.

[0059] In one aspect of the present invention, as shown in FIGS. 1 and 2, the sag value with respect to the base surface is made different according to the position on the spectacle lens in each defocus region. Thereby, the focus position brought about by the defocus region according to the position on the spectacle lens can be flexibly changed. Looking at it from another aspect, in one aspect of the present invention, the best position of the wave-optical contrast can be controlled. The reason will be described in detail below.

[0060] FIG. 3(a) is a graph when the defocus region has a spherical shape with a diameter of 1 mm and the refractive index of the spectacle lens is 1.59, with the vertical axis being VSOTF (Visual Strehl ratio based on OTF) and the horizontal axis being the defocus amount (unit: D (diopter), zero is the retinal position). FIG. 3(b) is an enlarged view of FIG. 3(a). The broken line is a plot when the refractive power of the defocus region is 3.50 D. The solid line is a plot when the refractive power of the defocus region is 4.00 D. The dotted line is a plot when the refractive power of the defocus region is 4.50 D. Settings other than the diameter of the defocus region and the refractive index of the spectacle lens adopt the description of Example 1 below.

[0061] FIG. 4(a) is a graph when the defocus region has a spherical shape with a diameter of 1 mm and a refractive power of 4.00 D and the refractive index of the spectacle lens is 1.59, with the vertical axis being VSOTF (Visual Strehl ratio based on OTF) and the horizontal axis being the defocus amount (unit: D (diopter), zero is the retinal position). FIG. 4(b) is an enlarged view of FIG. 4(a). The solid line is a plot when the refractive power of the defocus region is 4.00 D, and is the same as the plot shown in Figure 3(a). The dashed line is a plot when the solid defocus region is lowered by 0.23 μm (e.g., Figure 2). The dotted line is a plot when the solid defocus region is raised by 0.23 μm (e.g., Figure 1).

[0062] VSOTF is a scalar quantity that takes into account contrast sensitivity characteristics thought to be due to the retinal structure or nervous system. VSOTF is the sum of the real parts of OTF weighted to take into account the sensitivity characteristics of the eye for each spatial frequency. The specific formula is as follows:

number

[0063] VSOTF is described in the following literature: "Thibos LN, Hong X, Bradley A, Applegate RA. Accuracy and precision of objective refraction from wavefront aberrations. J Vis. 2004 Apr 23;4(4):329-51." and will not be described here.

[0064] OTF is a measure of lens performance, and represents the degree to which the contrast of an object can be faithfully reproduced on the image plane as a spatial frequency characteristic. A large MTF (Modulation Transfer Function) value, which is the absolute value of OTF, means that the wearer perceives a high contrast when viewing an object through the lens.

[0065] As shown in Figure 3(b), in addition to the light beam that is focused onto the retina (zero value on the horizontal axis) by the base region, the light beam converges in front of the retina and enters the retina as divergent light. The amount of defocus at that time varies depending on the refractive power of the defocus region.

[0066] 4(b), the inventors have found that by raising the defocus area, it is possible to reproduce the same situation as when the refractive power of the defocus area is increased, and by lowering the defocus area, it is possible to reproduce the same situation as when the refractive power of the defocus area is decreased.

[0067] Considering that the vertical axis is the VSOTF, it has been discovered that by utilizing the above findings, it is possible to provide a technology that can flexibly change the focus position that a defocus area should provide to a wearer according to the position on the spectacle lens. This finding will eventually lead to making it possible to provide the best focus position to a wearer of a spectacle lens having a defocus area according to the position of the defocus area. This principle will be explained below using an example. In the following example, a case is illustrated in which a plurality of spherical defocus areas are provided as convex areas that protrude in the +Z direction on the object-side surface.

[0068] First, the wavefront of the spectacle lens and Zernike polynomials may be utilized to calculate the focal position based on the VSOTF.

[0069] The wavefront of an eyeglass lens refers to the wavefront of a light beam whose diameter is defined by the pupil after passing through the eyeglass lens. The specification of the amount of wavefront progression w in each defocus region with respect to the base region is not particularly limited in its method, and can be performed, for example, by simulation processing using wave optics calculations.

[0070] The Zernike polynomial is a function (orthogonal polynomial) defined inside a unit circle with a radius of 1. Specifically, it is represented by the following equation (1).

[0071]

Equation

[0072] In equation (1), W(x, y) is the wavefront at coordinates x, y, Zj(x, y) is the j-th Zernike polynomial, cj is the Zernike coefficient corresponding to the j-th Zernike polynomial, and J is the number of Zernike polynomials used in the expansion.

[0073] According to such Zernike polynomials, all surface shapes can be (approximately) expressed by the sum of Zernike polynomials.

[0074] Figure 5 is an explanatory diagram showing a specific example of shape decomposition by Zernike polynomials.

[0075] Specifically, for example, for a certain surface shape, as shown in Figure 5, shape decomposition can be performed from the 0th-order aberration to the nth-order aberration (n is a natural number) by Zernike polynomials.

[0076] In the figure, each component surrounded by the frame near the center represents a rotationally symmetric component, and each other component represents a non-rotationally symmetric component. Also, in the figure, the component of the second-order aberration belonging to the rotationally symmetric component is generally called a defocus error (defocus), and the coefficient of the aberration corresponds to the focus position at which the wavefront aberration is minimized. The component of the fourth-order aberration belonging to the rotationally symmetric component is a component corresponding to spherical aberration. The sum of the coefficients of each component belonging to the rotationally symmetric component corresponds to the focus position at which the PSF (Point Spread Function) is minimized. The PSF may be obtained by the ray tracing method.

[0077] Also, for example, regarding the expansion coefficients in the above polynomial or orthogonal polynomial, the weights of the rotationally symmetric components (see Fig. 5) when expanded by the Zernike polynomial may be set to 1. If the weights of the rotationally symmetric components are set to 1, the focus position at which the PSF is minimized can be calculated. However, the weights of components having no significant amount may be omitted.

[0078] Zero The fact that the focus position can be calculated from the expansion coefficients of the Zernike polynomial can be explained as follows. Assume a case where a light beam is incident at an angle α on a surface of an eyeglass lens with a refractive index N that describes a gentle curve and exits at an angle α'. In that case, the sag value Z, which is the displacement amount from the base surface representing the lens shape, and the wavefront aberration W have the following proportional relationship.

Equation

Equation

[0079] The ray aberration (transverse aberration) Dx and Dy at a distance l from the lens can be expressed as the product of the derivative of the wavefront aberration W with respect to h and the F-number of the defocus area (when one defocus area is considered to be a lens) as shown in the formula below.

number

[0080] Generally, the focal point is defined in various ways depending on the idea or application, such as the position where the contrast of the target spatial frequency is highest, the position where energy is highest, the position where the dispersion of light rays is smallest, etc. The position where energy is highest is equivalent to "the position where the sum of the contrast of all spatial frequencies is highest," and the position where dispersion of light rays is smallest (specifically, the position where the PSF is smallest) is equivalent to "the position where the contrast of low spatial frequencies that are very close to zero is highest."

[0081] In the case of eyeglasses, since the peak of the eye's sensitivity characteristic is close enough to the low frequency range, it is reasonable to determine the focus position by prioritizing contrast at low frequencies. The focus position is the intermediate position between the position where the energy is highest and the position where the dispersion of light rays is smallest.

[0082] The position where the energy is highest corresponds to the so-called focal length, which can be calculated from the curvature of the wavefront. The position where the dispersion of the light rays is smallest is the focal position, which can be calculated from the amount of ray aberration as follows:

[0083] The focal position is the state where all defocus-induced aberrations contained in ray aberrations have been removed, in other words, the position where the remaining aberration after removing defocus aberrations is at its smallest. This can be expressed mathematically. The variance of the PSF, which is a function that represents the ray position on a certain image plane, is the sum of the squares of the lateral aberrations, as shown in the following equation.

number

[0084] The aberration due to the defocus amount P is a linear function of (hx, hy). Therefore, the position where the residual error is minimized when the aberration is approximated by a linear function in terms of the aberration amount is the position where the variance of the PSF is minimized. That is, the position shifted by the defocus amount from the image plane is the in-focus position. The following equation shows this situation.

Equation

[0085] Solving the above equation gives the following.

Equation

[0086] Here, the relationship between the wavefront aberration and the ray aberration is utilized. This relationship is obtained as follows based on the above [Equation 5].

Equation

[0087] Integrating the above equation by parts and converting it to polar coordinates gives the following equation. The defocus region is defined as a closed interval where r < 1, and the circumference where r = 1 is treated as the base region.

Equation

[0088] The first term inside the parentheses on the right side is the reciprocal of the square of the radius (φ / 2) in the plan view of the defocus region, so it is the reciprocal of the bottom area.

[0089] The first term inside the second parentheses on the right side is the integral value of the wavefront aberration over the entire defocus region. Since the wavefront aberration corresponds to the sag amount of the lens, this term corresponds to the integral of the sag amount of the lens, that is, the volume.

[0090] Since the defocus region is defined as a closed interval where r < 1, the height of the second term inside the second parentheses on the right side is the average height of the base surface surrounding the defocus region.

[0091] In summary, the second parentheses on the right side refers to the volume of the hatched portion in FIG. 1 or the hatched portion in FIG. 2. In the case of FIG. 1, since all the sag values of the three-dimensional shape of the defocus region in the second parentheses on the right side are positive, it refers to the entire volume of the hatched portion j. In the case of FIG. 2, the second parentheses on the right side refers to the value obtained by subtracting the volume of the hatched portion k below the base surface from the volume (hatched portion j) above the base surface in the defocus region.

[0092] That is, the defocus amount P and thus the focus position correspond to the value obtained by dividing the integral value of the sag values with respect to the height of the base surface (hereinafter also simply referred to as the "outermost periphery") adjacent to the defocus region and surrounding the periphery of the defocus region in a plan view by the bottom area of the defocus region.

[0093] More specifically, it is proportional to the value obtained by dividing the volume (integral value) of the portion having a positive sag value between the defocus region and the base surface by the bottom area of the defocus region after subtracting the volume (integral value) of the portion having a negative sag value between the defocus region and the base surface.

[0094] And the sum of the rotationally symmetric components of the Zernike polynomials is the integral value of the wavefront progress with respect to the outermost periphery of the defocus region. This corresponds to the integral value of the sag values with respect to the outermost periphery of the defocus region.

[0095] As a result of the above, by increasing or decreasing the sag value of the defocus region, and thus raising or sinking (in other words, bulging or digging) the defocus region, the focus position can be controlled.

[0096] Incidentally, in the case of glasses, it has been stated that the peak of the sensitivity characteristics of the eye is rather close to the low frequency side. And it has been stated that it is appropriate to determine the focus position while emphasizing the contrast at low frequencies.

[0097] For example, at mid-frequency waves, which are the average of all frequencies, the focus position determined by the MTF is roughly determined by the radius of curvature R of the defocus area. On the other hand, at low frequencies that are extremely close to zero, the focus position determined by the MTF is roughly determined by the integral value of the sag value Z when the outermost periphery of the defocus area is used as the reference. As a result, the focus position in the frequency characteristics of the eye (a combination of low to mid frequencies) is determined by the radius of curvature R and the integral value of the sag value Z.

[0098] For example, the focal position for the eye is the position closer to the retina when the distance between the geometric focal point determined by the radius of curvature R of the defocus area and the focal point determined by the integral value of the sag value Z of the defocus area (the best focal position at low frequencies) is divided into four equal parts. This is expressed as the following formula: ((Distance from the retina to the mid-frequency focal point) x 3 + (Distance from the retina to the low-frequency focal point)) / 4 = (Focus point for the eye, distance from the retina) The power of the defocused area that brings about this focus position is also called segment power.

[0099] If the base areas of the defocus areas were made equal, the focus of the defocus areas for the wearer could be controlled simply by increasing or decreasing the sag value of the defocus areas to move the defocus areas up or down. Note that "equal" here means that the error in the base area of each defocus area from the average value of the base areas of the defocus areas is 10% or less (preferably 5% or less, 3% or less, or 1% or less).

[0100] This makes it possible to change the focal position without changing the surface shape of the defocus area according to the position on the eyeglass lens. Compared to changing the surface shape according to the change in focal position, this simplifies manufacturing, allowing for the creation of null wavefronts during interferometric measurements to be done all at once.

[0101] In this specification, the "bottom area" refers to the area of the portion surrounded by the outermost circumference of the defocus region. When the sag value of the outermost circumference is positive, the area of the region overlapping with the base surface is taken as the bottom area. When the sag value of the outermost circumference is negative, the area of the portion surrounded by the most negative sag value is taken as the bottom area. The area of the defocus region (or convex region) in plan view may be adopted as the bottom area.

[0102] It has been described that the defocus power to be given to the wearer varies depending on the wearer or the position of the lens. This means increasing or decreasing the sag value of the defocus region according to the position of the defocus region on the spectacle lens. An example of this idea and its application is listed below.

[0103] (Power error: The predetermined position B where the sag value is relatively high is a position closer to the center of the lens) In the portion away from the center of the lens (the portion closer to the periphery of the lens, the peripheral part of the lens), since it is used during peripheral vision, spherical aberration and power error due to oblique incidence occur. Therefore, the defocus power brought to the wearer by the light beam incident and exiting with respect to the center of the lens is different from the defocus power brought to the wearer by the light beam incident and exiting with respect to the portion closer to the periphery of the lens.

[0104] To compensate for this difference, the predetermined position B may be a position closer to the center of the lens, and the predetermined position A may be a position closer to the periphery of the lens. That is, by setting the sag value of the defocus region high closer to the center of the lens and setting the sag value of the defocus region low closer to the periphery of the lens, the increase in diopter associated with the power error may be canceled. At this time, as shown in Fig. 2(b), in the three-dimensional shape of the defocus region a at the predetermined position A, the sag value in the vicinity of the base region may be negative. Of course, as shown in Fig. 1(b), the sag value of the entire three-dimensional shape of the defocus region a may be positive.

[0105] (Consideration of the image surface curvature of the eye optical system and the curvature of the retina at the peripheral part of the retina away from the fovea) Another example of the difference in defocus power caused by different positions on the spectacle lens is as follows.

[0106] The optical system of the eye has a curvature of field based on Petzval's law, but the curvature of the retina is stronger. Therefore, in general, the point where light beams converge in the peripheral part of the retina is deeper than the retina. In myopic people in particular, the axial length of the eye is elongated, which tends to make the curvature of the retina stronger and the point where light converges deeper.

[0107] In light of this, it is thought that eyeglasses with high peripheral defocus power should be prescribed to wearers who are estimated to have a high retinal curvature based on information such as measured retinal shape, axial length, and degree of myopia progression.

[0108] To achieve this, the predetermined position A may be closer to the center of the lens, and the predetermined position B may be closer to the periphery of the lens. In other words, the sag value of the defocus region may be set higher near the periphery of the lens and lower near the center of the lens to accommodate the curvature of the peripheral portion of the retina. In this case, the sag value near the base region in the three-dimensional shape of the defocus region a at the predetermined position A may be set to a negative value.

[0109] (Regarding the above curvature, if the lens periphery is asymmetric between the nose and ear sides) It is known that the curvature of the field of the eye and the curvature of the retina are asymmetric between the nasal and ear sides, and the degree of this asymmetricity varies from person to person. Side It is preferable to make it asymmetrical.

[0110] Furthermore, in the case of so-called high-curve lenses that are curved to fit the shape of the face, the incidence angle differs between the ear side and the nose side. In this case, too, it is necessary to set the defocus power asymmetrically to match the asymmetric incidence angle between the ear side and the nose side.

[0111] In this case, taking into consideration the asymmetry between the nose and ear sides, the degree of increase in the sag value may be different depending on whether it is closer to the nose side or closer to the ear side, even if it is closer to the lens. The predetermined position A may be the nose side, and the predetermined position B may be the ear side. Conversely, the predetermined position A may be positioned on the ear side, and the predetermined position B may be positioned on the nose side. At this time, the sag value near the base region in the three-dimensional shape of the defocus region a at a given position A may be negative.

[0112] <Preferred Examples and Modified Examples of Eyeglass Lenses> Preferred examples and modifications of the spectacle lens according to one aspect of the present invention will be described below.

[0113] The sag value of the entire three-dimensional shape of the defocus area a at the predetermined position A and the sag value of the entire three-dimensional shape of the defocus area b at the predetermined position may both be positive or negative.

[0114] If we assume that predetermined position B is closer to the periphery of the lens and predetermined position A is closer to the center of the lens, and both sag values are positive, defocus region b has a shape that is a raised portion of defocus region a (see, for example, Figure 1). Therefore, the volume of the convex region that includes defocus region b is larger than the volume of the convex region that includes defocus region a. Furthermore, the sag value at the center of the three-dimensional shape of defocus region b may be equal to the sag value at the center of the three-dimensional shape of defocus region a (or the entire three-dimensional shape in some cases) increased by a predetermined value. The shape of the base portion created by the raised portion may be appropriately set so that it connects to the base region.

[0115] If it is assumed that the specified position B is closer to the periphery of the lens and that the specified position A is closer to the center of the lens, the three-dimensional shape of the defocus region m at the intermediate position M may be used as the reference, and the defocus region b at the specified position B may be an increase in the sag value at the center of the 3-dimensional shape of the defocus region m (upholstery, raised), while the defocus region a at the specified position A may be an decrease in the sag value of the 3-dimensional shape of the defocus region m (sinking, excavation).

[0116] FIG. 6(a) is a schematic cross-sectional view when the increase amount of the sag value in the three-dimensional shape increases from the central portion toward the periphery, and FIG. 6(b) is a schematic cross-sectional view when the increase amount of the sag value in the three-dimensional shape decreases from the central portion toward the periphery. The dashed-dotted line indicates the three-dimensional shape of the defocus region before increasing the sag value.

[0117] As shown in FIG. 1, the increase amount of the sag value in the three-dimensional shape may be constant, or the increase amount may be changed according to the location of the three-dimensional shape as shown in FIGS. 6(a) and 6(b).

[0118] In the case of FIG. 1, at least in the central portion, the surface shapes of the defocus regions a and b are equal. Here, the “equal” means that at any location of each defocus region (for example, location a1 (e.g., the vertex of the convex region) in defocus region a, and location b1 (e.g., the vertex of the convex region) corresponding to location a1 in defocus region b), the error from the average value of the sag values of the three-dimensional shapes of each defocus region ((sag value of location a1 + sag value of location b1) / 2) is 10% or less (preferably 5% or less, 3% or less, 1% or less).

[0119] Whether it is FIG. 1 or FIGS. 6(a) and 6(b), the sag value of the above-mentioned location b1 becomes a value exceeding the sag value of the above-mentioned location a1. Examples of the above-mentioned location include at least either (preferably both) the vertex of the convex region and the outer edge of the convex region.

[0120] The radius of curvature of the central portion (in some cases, the whole) of the defocus region a and the radius of curvature of the central portion (in some cases, the whole) of the defocus region b may be made equal. In this case, the focus position can be flexibly changed while the surface shapes of the defocus regions remain equal to each other.

[0121] In this specification, "equal radii of curvature" means that the deviation from the average value of the radii of curvature at the center of each defocus area is 10% or less (preferably 5%, 3%, or 1% or less). Having equal radii of curvature at each defocus area means that the sag values (heights) are different at the center of each defocus area (or in some cases, the entire area) but have the same shape. This facilitates design and manufacturing (for example, forming the defocus area using inkjet or the like).

[0122] When the central portion of the defocus area has an aspherical shape, in addition to making both radii of curvature equal, the aspherical coefficients may also be equal. In this specification, "equal aspherical coefficients" means that the deviation from the average value of the aspherical coefficients at the central portion of each defocus area is 10% or less (preferably 5% or less, 3% or less, or 1% or less).

[0123] If the center of the defocus area has an aspherical shape, an approximate radius of curvature R may be used. The approximate radius of curvature R is expressed by the following formula, where C is the diameter of the circle that forms the outer edge in a plan view, and h is the sag value from the outer edge. R={h 2 +(C / 2) 2} / 2h

[0124] Approximately circular defocus regions may be arranged in an island pattern (i.e., spaced apart and not adjacent to each other) around the center of the eyeglass lens at equal intervals in the circumferential and radial directions. One example of the arrangement of the defocus regions in a planar view is an example in which the defocus regions are independently and discretely arranged so that the centers of the defocus regions are at the vertices of an equilateral triangle (the centers of the defocus regions are arranged at the vertices of a honeycomb structure). This arrangement is also called a "hexagonal arrangement." This example is mainly described in this specification.

[0125] It is preferable that more than half of the plurality of defocus regions (all defocus regions) are arranged at the same period in a plan view. An example of a pattern with the same period is the above hexagonal arrangement. The direction of the period may be the circumferential direction and / or the radial direction. Preferably, it is 80% or more, more preferably 90% or more, and still more preferably 95% or more. Hereinafter, preferred examples of "the number of more than half (or 80% or more) of all defocus regions" are 80% or more, 90% or more, and 95% or more in the preferred order as above, and repeated descriptions are omitted.

[0126] A set T of defocus regions that is 80% or more of all defocus regions, including defocus region a and defocus region b. In defocus region T, the radius of curvature of the center part of each is equal, and the number of defocus regions having the same sag value as defocus region a in defocus region T is 10 to 90%, and the number of defocus regions having the same sag value as defocus region b in defocus region T is preferably 10 to 90%. That is, it is preferable to ensure a considerable number of defocus regions a and defocus regions b.

[0127] When the sag value (e.g., maximum sag value) of the three-dimensional shape of defocus region a is the smallest among all defocus regions, it is preferable that in 80% or more of all defocus regions, the relationship "the sag value of the three-dimensional shape of defocus region b is a value obtained by increasing the sag value of the three-dimensional shape of defocus region a" is satisfied. This means that there are not only defocus region b but also defocus regions c, d, e... (all having a larger sag value than defocus region a and different amounts of increase in sag value from defocus region b) that satisfy the above relationship.

[0128] The defocus regions may be spherical, aspherical, toric, or a mixture of these (for example, the central portion of each defocus region may be spherical, and the peripheral portions outside the central portion may be aspherical). The boundary between the central portion and the peripheral portions may be provided at 1 / 3 to 2 / 3 of the radius of the defocus region (or convex portion region) in a planar view. However, it is preferable that at least the central portions of defocus region a and defocus region b have a convex curved surface shape that protrudes toward the outside of the lens. Furthermore, since it is preferable that more than half of the multiple defocus regions (all defocus regions) be arranged at the same period in a planar view, it is preferable that the defocus regions be spherical.

[0129] <Example of eyeglass lenses> The arrangement of the multiple defocus areas is not particularly limited, and can be determined from the viewpoint of, for example, visibility from outside the defocus areas, adding design features to the defocus areas, adjusting refractive power using the defocus areas, and the like.

[0130] Approximately circular defocus regions may be arranged in an island pattern (i.e., spaced apart and not adjacent to each other) around the center of the eyeglass lens at equal intervals in the circumferential and radial directions. An example of the arrangement of the defocus regions in a planar view is an independent, discrete arrangement in which the centers of the convex regions are at the vertices of equilateral triangles (hexagonal arrangement in which the centers of the defocus regions are located at the vertices of a honeycomb structure). In this case, the distance between the defocus regions may be 1.0 to 2.0 mm. The number of defocus regions may be 100 to 100,000.

[0131] Each defocus region is configured, for example, as follows: The diameter of the defocus region in plan view is preferably about 0.6 to 2.0 mm. The sag amount (protrusion height, protrusion amount) of the defocus region is about 0.1 to 10 μm, preferably 0.4 to 2.0 μm. The convex region has a spherical shape with a radius of curvature of 50 to 250 mm, preferably about 86 mm.

[0132] There is no limitation on the specific numerical value of the defocus power in each defocus area. For example, it is preferable that the minimum value of the defocus power brought about by the defocus area on the spectacle lens is within the range of 0.50 to 4.50 D, and the maximum value is within the range of 3.00 to 10.00 D. The difference between the maximum value and the minimum value is preferably within the range of 1.00 to 5.00 D.

[0133] The "defocus power (amount)" refers to the difference between the refractive power of each defocus area and the refractive power of the portion outside each defocus area. In other words, the "defocus power (amount)" is the difference obtained by subtracting the refractive power of the base portion from the average value of the minimum refractive power and the maximum refractive power at a predetermined location in the defocus area. In this specification, the case where the defocus area is a convex area is exemplified.

[0134] The "refractive power" in this specification refers to the average refractive power, which is the average value of the refractive power in the direction where the refractive power is minimum and the refractive power in the direction (perpendicular to this direction) where the refractive power is maximum.

[0135] The lens substrate is formed of, for example, a thermosetting resin material such as thiourethane, allyl, acrylic, or epithio. In addition, as the resin material constituting the lens substrate, other resin materials that can obtain a desired refractive power may be selected. Also, instead of the resin material, a lens substrate made of inorganic glass may be used.

[0136] The hard coat film is formed using, for example, a thermoplastic resin or a UV curable resin. The hard coat film can be formed by immersing the lens substrate in a hard coat liquid or using spin coating or the like. By coating such a hard coat film, the durability of the spectacle lens can be improved.

[0137] The antireflection film is formed by, for example, forming an antireflection agent such as ZrO2, MgF2, or Al2O3 by vacuum deposition. By coating such an antireflection film, the visibility of the image transmitted through the spectacle lens can be improved.

[0138] As described above, a plurality of defocus regions are formed on the object-side surface of the lens substrate. Therefore, when this surface is covered with a hard coat film and an anti-reflection film, a plurality of defocus regions are also formed by the hard coat film and the anti-reflection film, following the defocus regions in the lens substrate.

[0139] In manufacturing spectacle lenses, first, a lens substrate is molded by a known molding method such as cast polymerization. For example, a mold having a molding surface with a plurality of recesses is used to perform molding by cast polymerization, thereby obtaining a lens substrate having a defocus region on at least one surface. Once the lens substrate is obtained, a hard coat film is then formed on the surface of the lens substrate. The hard coat film can be formed by immersing the lens substrate in a hard coat solution, by spin coating, or the like. After the hard coat film is formed, an anti-reflection film is further formed on the surface of the hard coat film by vacuum deposition of an anti-reflection agent. By using such a manufacturing procedure, a spectacle lens having a plurality of defocus areas protruding toward the object side on the object side surface is obtained.

[0140] The thickness of the coating formed through the above steps may be, for example, in the range of 0.1 to 100 μm (preferably 0.5 to 5.0 μm, and more preferably 1.0 to 3.0 μm). However, the thickness of the coating is determined depending on the function required of the coating, and is not limited to the range exemplified above.

[0141] One or more additional coating layers can be formed on the coating layer. Examples of such coating layers include various coating layers such as anti-reflection coatings, water-repellent or hydrophilic anti-fouling coatings, and anti-fogging coatings. Known techniques can be applied to form these coating layers.

[0142] <Design method for eyeglass lenses> The present invention is also applicable to a method for designing spectacle lenses. Specifically, the spectacle lenses are designed by setting conditions so as to satisfy the above formula (1). Details of the content of each component of this design method are omitted because they overlap with the content described in <Spectacle Lenses>. Note that the technical idea of the present invention is also reflected in the method for manufacturing spectacle lenses designed using this design method. Hereinafter, one configuration of the method for designing spectacle lenses will be described. "A base region that causes a light beam incident from the object-side surface to exit from the eyeball-side surface and converge on the retina through the eyeball, a defocus region surrounded by the base region, the defocus region having a plurality of defocus regions through which at least a part of the light beam passing through the defocus region enters the retina as a divergent light, A method for designing a spectacle lens comprising: Based on the base surface constituted by the base region, when the direction of the normal line of the base surface toward the outside of the lens is defined as a positive sag value and the direction toward the inside of the lens is defined as a negative sag value, By increasing the sag value of the three-dimensional shape of the defocus region to raise the defocus region with respect to the base surface, or By decreasing the sag value of the three-dimensional shape of the defocus region to sink the defocus region with respect to the base surface, A method for designing a spectacle lens that changes the focus position according to the position on the spectacle lens where the defocus region is provided for the wearer." At this time, it is preferable to determine the sag value of each defocus region so as to correspond to changes in the focus position due to parameters related to the wearer, such as the degree of myopia progression, the state of the choroid, the incident angle during wearing, the aberration (image surface curvature) of the eye, and the curvature of the retina.

[0143] The technical scope of the present invention is not limited to the above-described embodiments, and includes forms in which various changes and improvements are made within the range in which specific effects obtained by the constituent elements of the invention and their combinations can be derived.

[0144] The eyeglass lens design method according to one aspect of the present invention may be performed using a computer device (e.g., a calculation unit within the device). In other words, the technical concept of the present invention is also reflected in an eyeglass lens design system using a computer device.

[0145] That is, a computer device configured with hardware resources such as a calculation unit having a CPU (Central Processing Unit) or the like, a memory such as a flash memory or an HDD (Hard Disk Drive), an input / output interface, etc. may be used, and a predetermined program pre-installed in the memory may be executed by the calculation unit to set the sag value of each defocus area according to the position of the defocus area on the spectacle lens. At this time, the parameters related to the wearer may be stored in the memory, or may be obtained from a cloud on a network.

[0146] Furthermore, the specified program for causing a computer device to design eyeglass lenses may be provided by being stored on a recording medium readable by the computer device (e.g., a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc.), as long as it can be installed on the computer device, or it may be provided from outside via a network such as the Internet or a dedicated line. [Example]

[0147] The present invention will now be described in detail with reference to examples, but the present invention is not limited to the following examples.

[0148] Examples 1A to 1C The following lens substrate was manufactured. Note that no other materials were laminated onto the lens substrate. The prescription power was S (spherical power) 0.00D and C (astigmatic power) 0.00D. Planar diameter of lens substrate: 100 mm Lens material type: PC (polycarbonate) Lens substrate refractive index: 1.589 Base curve of the lens substrate: 3.30 D Forming surface of the convex region: the surface on the object side Shape of the convex region: spherical surface Shape of the convex region in plan view: perfect circle (diameter 1 mm) Arrangement of the convex regions in plan view: discretely arranged independently such that the centers of the respective convex regions become the vertices of an equilateral triangle (the centers of the respective convex regions are arranged at the vertices of a honeycomb structure) Range where the convex regions are formed: within a circle with a radius of 23.5 mm from the lens center (however, excluding a regular hexagonal region with a circle having a radius of 3.0 mm from the lens center as an inscribed circle) Pitch between the respective convex regions (distance between the centers of the convex regions): 1.5 mm

[0149] In Examples 1A to 1C, the segment power was decreased from the lens center (near the lens center) toward the lens peripheral portion (near the lens periphery).

[0150] FIG. 7 is a graph in Example 1A when the vertical axis is the change amount of the sag value from the reference (unit: μm) and the horizontal axis is the position of the center in plan view of the defocus region (the origin is the lens center) (unit: mm). Hereinafter, this position is also referred to as the segment position. FIG. 8 is a graph in Example 1A when the vertical axis is the segment power (unit: D) and the horizontal axis is the position of the center in plan view of the defocus region (the origin is the lens center) (unit: mm).

[0151] In Example 1A, it was based on the three-dimensional shape of the defocus region arranged at the outermost periphery (hereinafter, the maximum sag value of the reference three-dimensional shape is 0.74 μm). And, the three-dimensional shape of the defocus region closer to the lens center as viewed from this defocus region was designed by increasing the sag value of this reference three-dimensional shape by a constant value to increase the bulk. As approaching the lens center, the constant value was increased. Note that the shape of the side surface of the newly formed base portion by increasing the bulk was a linear shape in cross-sectional view (Z-direction straight line) connecting the three-dimensional shape and the base surface while keeping the bottom area of the defocus region constant (for example, FIG. 1. Hereinafter, the same applies to increasing the bulk). As a result, the segment power increased in the defocus area closer to the lens center, and decreased in the defocus area farther from the lens center.

[0152] Figure 9 is a graph in Example 1B, where the vertical axis represents the change in sag value from the reference (unit: μm) and the horizontal axis represents the position of the center of the defocus area in a planar view (the origin is the center of the lens) (unit: mm). FIG. 10 is a graph in Example 1B, in which the vertical axis represents segment power (unit: D) and the horizontal axis represents the position of the center of the defocus area in a plan view (the origin is the lens center) (unit: mm).

[0153] In Example 1B, the three-dimensional shape of the defocus area located closest to the lens center was used as a reference. The three-dimensional shapes of defocus areas closer to the lens periphery as viewed from the defocus area were designed by reducing the sag value of this reference three-dimensional shape by a fixed value. As the distance from the lens center increases, the fixed value was increased, and the amount of reduction increased. As a result, the segment power increased in the defocus area closer to the lens center, and decreased in the defocus area farther from the lens center.

[0154] Figure 11 is a graph in Example 1C, where the vertical axis represents the increase in sag value from the reference (unit: μm) and the horizontal axis represents the position of the center of the defocus area in a planar view (the origin is the center of the lens) (unit: mm). FIG. 12 is a graph in Example 1C, in which the vertical axis represents segment power (unit: D) and the horizontal axis represents the center position of the defocus area in plan view (the origin is the lens center) (unit: mm).

[0155] In Example 1C, the three-dimensional shape of a defocus area whose center in plan view is located at a position 12.5 mm away from the center of the lens was used as the reference. The three-dimensional shape of the defocus area near the center of the lens was designed by increasing the sag value of this reference three-dimensional shape by a fixed value. The fixed value increased as the lens center was approached. The three-dimensional shape of the defocus area near the lens periphery was designed by reducing the sag value of this reference three-dimensional shape by a fixed value. The fixed value was increased as the distance from the lens center increased. As a result, the segment power increased in the defocus area closer to the lens center, and decreased in the defocus area farther from the lens center.

[0156] Examples 2A to 2C In Examples 2A to 2C, the segment power was increased from the lens center (closer to the center) toward the lens periphery (closer to the periphery).Other than that, the contents were the same as those described in Example 1.

[0157] Figure 13 is a graph in Example 2A, where the vertical axis represents the change in sag value from the reference (unit: μm) and the horizontal axis represents the position of the center of the defocus area in a planar view (the origin is the center of the lens) (unit: mm). FIG. 14 is a graph in Example 2A, in which the vertical axis represents segment power (unit: D) and the horizontal axis represents the position of the center of the defocus area in a plan view (the origin is the lens center) (unit: mm).

[0158] In Example 2A, the three-dimensional shape of the defocus area located at the outermost periphery was used as a reference. The three-dimensional shapes of the defocus areas closer to the center of the lens as viewed from the defocus area were designed by reducing the sag value of this reference three-dimensional shape by a fixed value. As the distance to the center of the lens increases, the fixed value was increased, and the amount of reduction was increased. As a result, the segment power of the defocus area becomes smaller as it approaches the lens center, and the segment power of the defocus area increases as it moves away from the lens center.

[0159] Figure 15 is a graph in Example 2B, where the vertical axis represents the change in sag value from the reference (unit: μm) and the horizontal axis represents the position of the center of the defocus area in a planar view (the origin is the center of the lens) (unit: mm). FIG. 16 is a graph in Example 2B, in which the vertical axis represents segment power (unit: D) and the horizontal axis represents the position of the center of the defocus area in plan view (the origin is the lens center) (unit: mm).

[0160] In Example 2B, the three-dimensional shape of the defocus area located closest to the lens center was used as a reference. The three-dimensional shapes of the defocus areas closer to the lens periphery as viewed from the defocus area were designed by increasing the sag value of this reference three-dimensional shape by a fixed value. The fixed value increased with increasing distance from the lens center. As a result, the segment power of the defocus area becomes smaller as it approaches the lens center, and the segment power of the defocus area increases as it moves away from the lens center.

[0161] Figure 17 is a graph for Example 2C, in which the vertical axis represents the increase in sag value from the reference (unit: μm) and the horizontal axis represents the position of the center of the defocus area in a planar view (the origin is the center of the lens) (unit: mm). FIG. 18 is a graph in Example 2C, in which the vertical axis represents segment power (unit: D) and the horizontal axis represents the position of the center of the defocus area in a plan view (the origin is the lens center) (unit: mm).

[0162] In Example 2C, the three-dimensional shape of a defocus area whose center in plan view is located at a position 12.5 mm away from the lens center was used as the reference. The three-dimensional shape of the defocus area near the center of the lens was designed by reducing the sag value of this reference three-dimensional shape by a fixed value. As the lens center was approached, the fixed value was increased, and the amount of reduction was increased. The three-dimensional shape of the defocus area near the lens periphery as seen from the defocus area was designed by increasing the sag value of the reference three-dimensional shape by a certain value to make it thicker. As the distance from the lens center increases, the certain value was increased. As a result, the segment power becomes smaller in the defocus area closer to the lens center, and the segment power of the defocus area increases as the distance from the lens center increases.

Explanation of symbols

[0163] 1 ··· Base area 1s ··· Base surface 2 ··· Defocus area 3 ··· Base part 4 ··· Concave part

Claims

1. a base region that emits a light beam incident from a surface on the object side from a surface on the eyeball side and converges it onto the retina through the eyeball; a plurality of defocus regions that are defocus regions surrounded by the base region and have the property that a light beam passing through at least a part of the defocus region enters the retina as a divergent light; comprising; the defocus region includes a defocus region a provided at a predetermined position A on the spectacle lens and a defocus region b provided at a predetermined position B; when, with reference to the base surface constituted by the base region, the direction normal to the base surface and directed outward of the lens is defined as a positive sag value and the direction directed inward of the lens is defined as a negative sag value, the sag value of the three-dimensional shape of the defocus region b is a value obtained by increasing the sag value of the three-dimensional shape of the defocus region a, and a spectacle lens, wherein the three-dimensional shape of the defocus region b is a shape obtained by thickening the three-dimensional shape of the defocus region a.

2. The spectacle lens according to claim 1, wherein when the three-dimensional shape of the defocus region a and the three-dimensional shape of the defocus region b are assumed to be aligned and overlapped with respect to the center or centroid in plan view and the base surface, the three-dimensional shape of the defocus region a does not protrude from the three-dimensional shape of the defocus region b.

3. The spectacle lens according to claim 1, wherein when the three-dimensional shape of the defocus region a and the three-dimensional shape of the defocus region b are assumed to be aligned and overlapped with respect to the center or centroid in plan view and the base surface, the three-dimensional shape of the defocus region a does not contact the three-dimensional shape of the defocus region b.

4. at least the central portions of the defocus region a and the defocus region b have a curved surface shape protruding outward of the lens, The spectacle lens according to any one of claims 1 to 3, wherein the radius of curvature of the central portion of the defocus region a is equal to the radius of curvature of the central portion of the defocus region b.

5. The spectacle lens according to any one of claims 1 to 4, wherein the increase amount of the sag value corresponding to the location of the three-dimensional shape of the defocus region b is constant.

6. The spectacle lens according to any one of claims 1 to 5, wherein the bottom area of the defocus region a is equal to the bottom area of the defocus region b.

7. the predetermined position A is a position near the periphery of the lens, the predetermined position B is a position near the center of the lens, or The predetermined position A is a position closer to the center of the lens, and the predetermined position B is a position closer to the periphery of the lens. The spectacle lens according to any one of claims 1 to 6.

8. In the three-dimensional shape of the defocus region a, the sag value in the vicinity of the base region is negative. The spectacle lens according to any one of claims 1 to 7.

9. A set T of defocus regions that are 80% or more of all defocus regions and include the defocus region b and the defocus region a. In the defocus region T, the radius of curvature of each central portion is equal, and the number of defocus regions having the same sag value as the defocus region a in the defocus region T is 10% to 90%, and the defocus region T The number of defocus regions having the same sag value as the defocus region b is 10% to 90%. The spectacle lens according to any one of claims 1 to 8.

10. When it is assumed that the three-dimensional shape of the defocus region a and the three-dimensional shape of the defocus region b are aligned and overlapped with the center or centroid in plan view and the base surface, the three-dimensional shape of the defocus region a does not contact the three-dimensional shape of the defocus region b. At least the central portions of the defocus region a and the defocus region b have a curved surface shape that protrudes toward the outside of the lens. The increase amount of the sag value corresponding to the location of the three-dimensional shape of the defocus region b is constant. The radius of curvature of the central portion of the defocus region a is equal to the radius of curvature of the central portion of the defocus region b. The bottom area of the defocus region a is equal to the bottom area of the defocus region b. The predetermined position A is a position closer to the periphery of the lens, and the predetermined position B is a position closer to the center of the lens, or The predetermined position A is a position closer to the center of the lens, and the predetermined position B is a position closer to the periphery of the lens, [[ID= ​ The spectacle lens according to any one of claims 1 to 10, wherein the spectacle lens is a myopia progression-inhibiting lens.

12. A base region that emits a light beam incident from the object side surface from the eyeball side surface and converges it onto the retina through the eyeball, and a plurality of defocus regions that are defocus regions surrounded by the base region, and at least a part of the light beam passing through at least a part of the defocus region has a property of entering the retina as divergent light, A method for designing a spectacle lens comprising: Based on the base surface constituted by the base region, when the direction along the normal direction of the base surface and outward from the lens is defined as a positive sag value and the direction toward the inside of the lens is defined as a negative sag value, By increasing the sag value of the three-dimensional shape of the defocus region to raise the defocus region with respect to the base surface, or By decreasing the sag value of the three-dimensional shape of the defocus region to sink the defocus region with respect to the base surface, A method for designing a spectacle lens that changes the focus position according to the position on the spectacle lens where the defocus region is provided for the wearer.

13. The method for designing a spectacle lens according to claim 12, wherein the focus position is changed by changing a value obtained by dividing, by the bottom area of the defocus region, a value obtained by subtracting the volume of a portion having a negative sag value between the defocus region and the base surface from the volume of a portion having a positive sag value between the defocus region and the base surface.

14. When assuming that the three-dimensional shape of the defocus region before and after the raising is aligned with the center or centroid in plan view and the base surface and overlaid, the three-dimensional shape of the defocus region before the raising does not protrude from or contact the three-dimensional shape of the defocus region after the raising, or The method for designing a spectacle lens according to claim 12 or 13, wherein when assuming that the three-dimensional shape of the defocus region before and after the sinking is aligned with the center or centroid in plan view and the base surface and overlaid, the three-dimensional shape of the defocus region after the sinking does not protrude from the three-dimensional shape of the defocus region before the sinking.

15. When assuming that the three-dimensional shapes of the defocus regions before and after the protrusion are aligned with the center or centroid in plan view and the base surface and superposed, the three-dimensional shape of the defocus region before the protrusion does not contact the three-dimensional shape of the defocus region after the protrusion, or The method for designing an ophthalmic lens according to claim 12 or 13, wherein when assuming that the three-dimensional shapes of the defocus regions before and after the depression are aligned with the center or centroid in plan view and the base surface and superposed, the three-dimensional shape of the defocus region after the depression does not contact the three-dimensional shape of the defocus region before the depression.

Images