Eyeglass lens

Abstract

Provided is an eyeglass lens 1 configured to cause rays that have entered from an object-side surface 3 to be emitted from an eyeball-side surface 4, and cause the emitted rays to converge at a predetermined position A. The eyeglass lens 1 includes a lens substrate 2 having a plurality of substrate convex portions 6 on at least one of the object-side surface 3 and the eyeball-side surface 4, and a coating film covering the surface provided with the substrate convex portions 6. The shape of convex portions present on the outermost surface of the eyeglass lens located on a side on which the substrate convex portions 6 are provided is an approximate shape of the substrate convex portions configured to cause rays that have entered the eyeglass lens 1 to converge at a position B that is closer to the object than the predetermined position A is.

Description

eyeglass lenses

[0001] The present invention relates to eyeglass lenses.

[0002] Patent Document 1 describes a spectacle lens that suppresses the progression of refractive errors such as myopia. Specifically, spherical micro-convex portions (substrate convex portions in this specification) with a diameter of, for example, about 1 mm are formed on the convex surface, which is the object-side surface of the spectacle lens. In spectacle lenses, light rays incident from the object-side surface are typically emitted from the eyeball-side surface and focused on the wearer's retina (predetermined position A in this specification). Meanwhile, light rays that pass through the micro-convex portions are focused at position B, which is closer to the object side than the predetermined position A, of the light rays incident on the spectacle lens. As a result, the progression of myopia is suppressed.

[0003] U.S. Patent Application Publication No. 2017 / 0131567

[0004] The present inventors have discovered that if the coating (e.g., hard coat film or anti-reflection film) provided on the surface on which the micro-convex portions are provided (the convex surface on the object side) of the eyeglass lens described in Patent Document 1 is the same as that of a conventional coating, the effect of inhibiting the progression of myopia may be reduced.

[0005] An object of one embodiment of the present invention is to provide a technique that can fully exert the myopia suppression effect even after a coating is formed on a lens substrate.

[0006] The present inventors have conducted extensive research to solve the above-mentioned problems. The coating covers the surface of the substrate having convex portions. In this case, the outermost surface shape of the coating has coating convex portions derived from the convex portions of the substrate.

[0007] In the absence of a coating, the convex portion of the substrate causes the focal point to be formed at a position closer to the object side than the predetermined position A. However, when a coating is formed on the lens substrate, whether the focal point is formed at the same position as or near the convex portion of the substrate depends on the shape of the outermost surface of the coating, i.e., the shape of the convex portion of the coating.

[0008] The present inventors have therefore come up with the following method. They have discovered that the myopia suppression effect can be fully achieved when the shape of the convex portions on the outermost surface of a spectacle lens is made to approximate the shape of the substrate convex portions. Preferably, the substrate convex portion shape (i.e., a partial spherical shape) is imagined from the actual coating convex portion shape. They have discovered that if the difference between this imagined partial spherical shape and the actual coating convex portion shape remains within a predetermined value, the myopia suppression effect can be further achieved.

[0009] The present invention was devised based on the above findings. A first aspect of the present invention is a spectacle lens that causes light rays incident on an object-side surface to exit from an eyeball-side surface and converge at a predetermined position A, the spectacle lens comprising: a lens substrate having a plurality of substrate convex portions on at least one of the object-side surface and the eyeball-side surface; and a coating covering the surface having the substrate convex portions, wherein the shape of the coating convex portions on the outermost surface of the spectacle lens on the side having the substrate convex portions is an approximation of the shape of the substrate convex portions that converges light rays incident on the spectacle lens at a position B that is closer to the object side than the predetermined position A.

[0010] A second aspect of the present invention is the aspect described in the first aspect, wherein, among a large number of light rays that are evenly incident within a predetermined range on the object-side surface of the eyeglass lens and pass through the coating, which are obtained by ray tracing calculation, the number of stray light rays that do not pass near the predetermined position A and do not pass near the position B closer to the object side is 30% or less of the number of incident light rays.

[0011] A third aspect of the present invention is the spectacle lens according to the first or second aspect, wherein a cross-sectional curve of astigmatism at the base of the coating convex portion in the astigmatism distribution for the outermost surface shape of the coating is 0.20 mm or less.

[0012] A fourth aspect of the present invention is a spectacle lens according to any one of the first to third aspects, wherein the maximum absolute value of the difference in the lens thickness direction between the spherical surface that is optimally approximated to the coating convex portion shape and the actual coating convex portion shape is 0.1 μm or less.

[0013] A fifth aspect of the present invention is the aspect according to any one of the first to fourth aspects, wherein the protruding distance L of the coating convex portion isｃ and the protruding distance L of the base material convex portion. ｌ The relationship between these satisfies the following formula (1): 0.6≦L ｃ / L ｌ ≦1.5...Formula (1)

[0014] The following other aspects can be applied to each of the above aspects.

[0015] In another aspect of the present invention, the coating convex portion converges light rays incident on the eyeglass lens to a position B that is closer to the object side than the predetermined position A by a range of more than 0 mm and not more than 10 mm.

[0016] In another aspect of the present invention, the coating comprises a λ / 4 film in contact with the lens substrate, a hard coat film formed on the λ / 4 film, and an anti-reflection film formed on the hard coat film.

[0017] In another aspect of the present invention, the refractive index of the lens substrate is higher than that of the λ / 4 film, and the refractive index of the λ / 4 film is higher than that of the hard coat film.

[0018] In another embodiment of the present invention, the stray light rate may be set to more than 0% (or 1% or more, or even 3% or more) and 30% or less. Furthermore, since it is preferable to reduce the stray light rate, it is preferably set to 20% or less, and more preferably set to 15% or less.

[0019] In another aspect of the present invention, the maximum absolute value of the difference in the lens thickness direction between the spherical surface that is optimally approximated to the coating convex portion shape and the actual coating convex portion shape is preferably 0.06 μm or less.

[0020] In another aspect of the present invention, the outermost surface of the spectacle lens (i.e., the outermost surface of the coating) has a shape that converges light rays incident on the spectacle lens to position B, which is closer to the object side than predetermined position A by a range of more than 0 mm and not more than 10 mm. The range is preferably 0.1 to 7 mm, more preferably 0.1 to 5 mm, and even more preferably 0.3 to 3 mm.

[0021] Further aspects of the present invention will be described below. The following aspects can be applied instead of the first aspect. Furthermore, the above-described aspects can be applied to the following aspects.

[0022] Yet another aspect of the present invention is a spectacle lens that causes light rays incident from an object-side surface to exit from an eyeball-side surface and converge at a predetermined position A, the spectacle lens comprising a lens substrate having a plurality of substrate convex portions on at least one of the object-side surface and the eyeball-side surface, and having a configuration that suppresses the generation of stray light rays that do not pass near the predetermined position A and do not pass near a position B that is closer to the object side than the predetermined position A.

[0023] Yet another aspect of the present invention is a spectacle lens that causes light rays incident from an object-side surface to exit from an eyeball-side surface and converge at a predetermined position A, the spectacle lens comprising: a lens substrate having a plurality of substrate convex portions on at least one of the object-side surface and the eyeball-side surface; and a coating covering the surface having the substrate convex portions, wherein the coating is 3.0 μm or less.

[0024] Yet another aspect of the present invention is a spectacle lens that causes light rays incident from an object-side surface to exit from an eyeball-side surface and converge at a predetermined position A, the spectacle lens comprising: a lens substrate having a plurality of substrate convex portions on at least one of the object-side surface and the eyeball-side surface; and a coating covering the surface having the substrate convex portions, wherein the convex portions on the outermost surface of the spectacle lens on the side having the substrate convex portions and the substrate convex portions have a common light convergence characteristic.

[0025] According to one embodiment of the present invention, it is possible to sufficiently exert the myopia suppression effect even after forming a coating on the lens substrate.

[0026] FIG. 1 is a cross-sectional view showing an example of an eyeglass lens according to one embodiment of the present invention. FIG. 2 is a schematic side cross-sectional view showing how an eyeglass lens according to one embodiment of the present invention causes a light ray incident from the object-side surface to exit from the eyeball-side surface and converge at a predetermined position A on the retina of the eyeball by a portion other than the coating convex portion (i.e., the base portion). FIG. 3 is a schematic side cross-sectional view showing how an eyeglass lens according to one embodiment of the present invention causes a light ray incident from the object-side surface to exit from the eyeball-side surface and converge at a position B closer to the object side than the predetermined position A by a coating convex portion. FIG. 4 is a schematic cross-sectional view showing the coating convex portion and the imaginary partial spherical shape of an actual eyeglass lens. FIG. 5 is a flowchart showing the flow of an eyeglass lens inspection method according to one embodiment of the present invention. FIG. 6 is a diagram (part 1) for explaining a method of identifying the position at which light rays converge. FIG. 7 is a diagram (part 2) for explaining a method of identifying the position at which light rays converge. FIG. 8 is a diagram (part 3) for explaining a method of identifying the position at which light rays converge. FIG. 9 is a flowchart showing a method of identifying the position at which light rays converge. FIG. 10 is a diagram showing a plot (solid line) of the astigmatism distribution (i.e., the astigmatism cross-sectional curve) in a cross section passing through the apex of the substrate convex portion (i.e., the center of the substrate convex portion in plan view) in the astigmatism distribution for the substrate convex portion and its vicinity, which is a design value (i.e., without a coating). FIG. 11 is a diagram showing a plot (solid line) of the astigmatism distribution (i.e., the astigmatism cross-sectional curve) in a cross section passing through the apex of the coating convex portion (i.e., the center of the coating convex portion in plan view) in the astigmatism distribution for the actual coating convex portion and its vicinity. FIG. 12(a) is a schematic cross-sectional view showing the coating convex portion and the substrate convex portion of an actual eyeglass lens. FIG. 12(b) is a schematic cross-sectional view in which the apex of the coating convex portion and the apex of the substrate convex portion are aligned. FIG. 13 is a plot showing the correlation equation between the value (defocus value) (horizontal axis) obtained by subtracting the surface refractive power of the substrate base portion from the surface refractive power of the substrate convex portion, and the defocus power (vertical axis) calculated from the reciprocal of the focusing position. FIG. 14( a) is a diagram showing a case where, in plan view, an independent, discrete arrangement is adopted in which the center of each coated protrusion is at the vertex of an equilateral triangle (the center of each coated protrusion is positioned at the vertex of the honeycomb structure), and FIG. 14( b) is a diagram showing a case where, in plan view, a structure is adopted in which each coated protrusion is positioned in a line.

[0027] Hereinafter, embodiments of the present invention will be described. The following description based on the drawings is merely an example, and the present invention is not limited to the illustrated embodiments. In the following definitions, it is preferable that more than 50% of all coating convex portions (or more than 50% of all substrate protrusions) satisfy the following definitions. More preferable are 80% or more, 90% or more, 95% or more, and 99% or more, in that order, and repeated descriptions will be omitted.

[0028] Fig. 1 is a cross-sectional view showing an example of a spectacle lens 1 according to one embodiment of the present invention. Fig. 1 shows an example in which the object-side surface 3 is convex and the eyeball-side surface 4 is concave (an example of a so-called meniscus lens).

[0029] A spectacle lens 1 according to one aspect of the present invention has an object-side surface 3 and an eyeball-side surface 4. The "object-side surface 3" is the surface that is located on the object side (forward, nearer in the Z direction) when a wearer wears eyeglasses equipped with the spectacle lens 1, and the "eyeball-side surface 4" is the opposite, i.e., the surface that is located on the eyeball side (rear, farther in the Z direction) when a wearer wears eyeglasses equipped with the spectacle lens 1. In this specification, the left-right (horizontal) direction when the spectacle lens is viewed from the front is defined as the X direction, the up-down direction as the Y direction, and the lens thickness direction and optical axis direction as the Z direction.

[0030] In a spectacle lens 1 according to one aspect of the present invention, the base portion (substrate base portion) of the lens substrate 2, excluding the micro-protrusions described in Patent Document 1 (i.e., the substrate protrusions 6 described below and the coating protrusions 11 thereon), and the outermost base portion (coating base portion) thereon, function to converge light rays incident from the object-side surface 3 to a predetermined position A by emitting the light rays from the eyeball-side surface 4 (i.e., the function to achieve the prescribed power), similar to conventional spectacle lenses 1. The term "convergence" here refers to convergence in at least one of the vertical and horizontal directions. Furthermore, the convergence point does not have to be single, and the convergence point may vary in the optical axis direction depending on the location within one coating protrusion 11. This convergence occurs not only in the spectacle lens 1 but also when light passes through the wearer's eye; however, for the sake of convenience, this will not be described hereinafter.

[0031] FIG. 2 is a schematic side cross-sectional view showing how a spectacle lens 1 according to one embodiment of the present invention causes light rays incident on the object-side surface 3 to exit from the eyeball-side surface 4 by using the portion other than the coating convex portion 11 (i.e., the coating base portion) and converge at a predetermined position A on the retina 20A of the eyeball 20.

[0032] A spectacle lens 1 according to one aspect of the present invention includes a lens substrate 2. The lens substrate 2 also has an object-side surface 3 and an eyeball-side surface 4. The shapes of both surfaces of the lens substrate 2 may be determined depending on the type of spectacle lens 1, and may be convex, concave, or flat, or a combination thereof.

[0033] A coating is formed so as to cover at least one of the object-side surface and the eyeball-side surface of the lens substrate 2, thereby forming the eyeglass lens 1.

[0034] In a lens substrate 2 according to one aspect of the present invention, a plurality of substrate convex portions 6 are formed on at least one of the object-side surface 3 and the eyeball-side surface 4. A coating is formed on these substrate convex portions 6, and in a state in which coating convex portions 11 derived from the substrate convex portions 6 are formed on the outermost surface shape of the coating, these coating convex portions 11 converge light rays incident on the eyeglass lens 1 to a position B that is closer to the object side than a predetermined position A.

[0035] 3 is a schematic side cross-sectional view showing how a spectacle lens 1 according to one embodiment of the present invention causes a light ray incident on the object-side surface 3 to exit from the eyeball-side surface 4 by the coating convex portions 11 and converge at a position B closer to the object side than a predetermined position A. Note that this convergence position B is determined by the arrangement B according to each of the plurality of coating convex portions 11. １ , B ２ , B ３ , ...B Ｎ The convergence position B in this specification exists as １ , B ２ , B ３ , ...B Ｎ This is a summary expression.

[0036] In one aspect of the present invention, the shape of the convex portion (e.g., coating convex portion 11) on the outermost surface of the eyeglass lens on the side having the substrate convex portion 6 is an approximate shape of the substrate convex portion that converges light rays incident on the eyeglass lens to position B, which is closer to the object side than the predetermined position A.

[0037] The approximate shape of the substrate convex portion refers to a shape in which the shape of the substrate convex portion 6 is approximated to a spherical surface (hereinafter referred to as a virtual partial spherical shape) that is optimally approximated to the shape of the coating convex portion 11 .

[0038] A specific example of the approximate shape of the substrate convex portions is as follows: It is preferable that the maximum absolute value of the difference in the lens thickness direction between the spherical surface that is optimally approximated to the shape of the coating convex portions 11 and the actual shape of the coating convex portions 11 is 0.1 μm or less (preferably 0.06 μm or less).

[0039] The following describes the advantages of defining the virtual partial spherical shape and the difference.

[0040] Without the coating, the substrate convex portion 6 has an approximately partially spherical shape, and the focal point is formed at position B closer to the object side. Even if a coating is formed on the lens substrate 2 and the coating convex portion 11 has a duller shape than the substrate convex portion 6, at least the apex portion of the coating convex portion 11 has a shape that follows the shape of the substrate convex portion 6.

[0041] In one aspect of the present invention, a spherical surface that is optimally approximated to the approximate partial spherical shape of the vertex of the coating projection 11 is hypothesized. This results in a hypothetical partial spherical shape. This hypothetical partial spherical shape is then compared with the actual shape of the coating projection 11.

[0042] 4 is a schematic cross-sectional view showing the coating convex portion 11 and the imaginary partial spherical shape of the actual spectacle lens 1. The solid line indicates the coating convex portion 11 of the actual spectacle lens 1, the dashed line indicates the imaginary partial spherical shape, the dashed-dotted line indicates the coating base portion of the actual spectacle lens 1, and the horizontally hatched portion indicates the difference in the lens thickness direction between the imaginary partial spherical shape and the actual shape of the coating convex portion 11.

[0043] The virtual partial spherical shape is a partial shape of a spherical surface that is optimally approximated to the shape of the coating convex portion 11 of the actual eyeglass lens 1. This virtual partial spherical shape is obtained by, for example, the least squares method.

[0044] A specific example of the optimal approximation is as follows: A spherical shape is placed so as to overlap the shape of the coating convex portion 11. From the shape of the base portion on the outermost surface of the eyeglass lens 1, from where the rising starts and moves toward the apex to where the rising ends, the difference between the two shapes in the lens thickness direction (optical axis direction, Z axis) is squared. A virtual partial spherical shape is set so that the sum of these values ​​is minimized.

[0045] As a method other than the least squares method, a virtual partial spherical shape may be obtained from the positions of the vertex of the coating convex portion 11 and multiple points in its vicinity. In this case, the vertex of the virtual partial spherical shape may be matched with the vertex of the coating convex portion 11 of the actual eyeglass lens 1, and the difference may be examined.

[0046] If the maximum absolute value of this difference is 0.1 μm or less (preferably 0.06 μm or less), the coating convex portion 11 will be very close to a partially spherical shape. As a result, the myopia suppression effect can be fully exerted. Furthermore, by applying this regulation, in addition to being able to fully exert the myopia suppression effect, it becomes unnecessary to take the trouble of exposing the cross section of the actually manufactured eyeglass lens 1 to check whether the coating convex portion shape faithfully reflects the substrate convex portion shape.

[0047] The rising start point from the shape of the base portion on the outermost surface may be the point where the curve obtained by first differentiating the curve of the coating convex portion 11 turns to an increase. Alternatively, the rising end point may be the rising portion of the peak of the astigmatism cross-sectional curve shown in FIG. 11(b) described later. The rising end point may also be set in a similar manner.

[0048] Further specific examples, preferred examples, and modifications of one aspect of the present invention will be described below.

[0049] In one aspect of the present invention, of the many rays of light that are evenly incident within a predetermined range on the object-side surface of the spectacle lens and pass through the coating, as obtained by ray tracing calculation, it is preferable to set the number of stray rays that do not pass near a predetermined position A and that do not pass near a position B closer to the object side to 30% or less of the number of incident rays.

[0050] The benefits of reducing stray light rays and the ratio of stray light rays (hereinafter also referred to as stray light ratio) will be described below.

[0051] Stray light rays are light rays that enter the object-side surface 3 of the spectacle lens 1 and exit from the eyeball-side surface 4, and do not pass near a predetermined position A where the light rays converge by the spectacle lens 1 itself, nor near a position B where the light rays converge by the substrate convex portion 6 and, in turn, the coating convex portion 11. Stray light rays cause blurring in the wearer's field of vision. For this reason, it is preferable to reduce the stray light rate of light rays that enter the object-side surface 3 of the spectacle lens 1 and exit from the eyeball-side surface 4.

[0052] One of the reasons for the occurrence of stray light rays is the coating. If the change in shape from the convex surface, which is the base surface 3 on the object side, at the base of the coating convex portion 11 is too gradual, the shape will deviate from the spherical shape of the substrate convex portion 6 and also from the convex surface, which is the object side surface 3. In this case, the light will not be focused on the wearer's retina 20A (near the predetermined position A in this specification) or near the position B closer to the object side.

[0053] On the other hand, by setting the stray light rate to 30% or less, as in the spectacle lens 1 of one embodiment of the present invention described above, it becomes possible to fully exert the myopia suppression effect even after a coating is formed on the lens substrate 2.

[0054] Ray tracing calculations are used to set and calculate the stray light rate. The calculations assume a situation in which a large number of light rays are uniformly incident within a predetermined range on the object-side surface of the eyeglass lens and pass through the coating (the situation in which the eyeglass lens is worn to view the outside world). This "predetermined range" may be any optical zone on the object-side surface. This optical zone refers to the portion of the object-side surface and the opposing eye-side surface that has a curved shape that achieves the power set for each wearer.

[0055] One of the reasons for the generation of stray light rays is a coating, and considering that a coating is essential for the spectacle lens 1 of one aspect of the present invention, the stray light rate may be set to more than 0% (or 1% or more, or even 3% or more) and 30% or less. Furthermore, since it is preferable to reduce the stray light rate, it is preferable to set it to 20% or less, and more preferably 15% or less.

[0056] The conditions for determining the stray light ratio are as follows: Fig. 5 is a flowchart showing the flow of an inspection method for eyeglass lenses according to one aspect of the present invention.

[0057] 5 , first, in step 101, the shape of the object-side surface (hereinafter also referred to as the convex surface) of the actual eyeglass lens 1 is measured, and curved surface data representing the shape of the convex surface 3 is created (shape measurement step). The shape of the convex surface 3 is measured, for example, by a non-contact three-dimensional microscope that performs length measurement using the interference of light. The three-dimensional shape of the convex surface 3 is acquired, for example, as discrete three-dimensional data (x, y, z).

[0058] Next, in step 102, curved surface data is generated from the obtained data representing the convex surface shape of the eyeglass lens 1 (curved surface data generation step). When discrete three-dimensional data is used as the data representing the convex surface shape of the eyeglass lens 1, for example, a set of B-spline curves may be generated. Furthermore, when the measured discrete three-dimensional data contains noise, for example, a moving average process may be performed to use the average value.

[0059] Next, in step 103, a model of the actual spectacle lens 1 is set based on the curved surface data (model setting step).

[0060] An eyeball model is also set up along with a model of the actual eyeglass lens 1. The eyeball model may use information related to the wearer (e.g., axial length, amount of eye accommodation, etc.). At this time, the eyeglass lens model 30 may be positioned relative to the eyeball model 32, taking into consideration the inclination (forward tilt angle and frame tilt angle) of the eyeglass lens when attached to the frame.

[0061] Next, in step 104, a ray tracing process is performed to identify the position at which the light rays converge most when they pass through the actual eyeglass lens 1 (convergence position identification step). Specifically, a PSF (Point Spread Function) is calculated for a model based on the curved surface data of the actual eyeglass lens 1, which represents the luminance distribution of the light rays emitted from a point light source at infinity and after they pass through the model.

[0062] The PSF can be obtained by tracing a large number of light rays emitted from a point light source and calculating the density of spots on an arbitrary surface. The PSFs of multiple arbitrary surfaces are then compared to identify the position (surface) where the light rays are most concentrated among the multiple arbitrary surfaces. The diameter of the light rays can be set based on the diameter of the light rays, and can be, for example, 4φ.

[0063] Here, a method for identifying the position where the light beam is most focused in step 104 will be described in more detail. Figures 6 to 8 are diagrams for explaining the method for identifying the position where the light beam is most focused. Figure 9 is a flowchart showing the method for identifying the position where the light beam is most focused.

[0064] First, as shown in Fig. 6, in step 201, a situation is assumed in which light rays pass through a convex coating 36 on the model on the object-side surface (convex surface) 33 on the model. Then, measurement planes P1,1 to P1,n are set at a predetermined distance Δd (e.g., 0.1 mm) from a 0 mm position on the retina 32A of the eyeball model 32 (e.g., a position of approximately 16 mm, which is the thickness of the vitreous body of the eyeball) to the retina 32A. Note that the distance Δd may be set to 0.2 mm or 1 / 50 of the axial length.

[0065] Next, in step 202, ray tracing is performed to calculate the density of rays on each measurement surface P1,1 to P1,n. The ray density can be calculated, for example, by setting a lattice-like grid (e.g., 0.1 mm x 0.1 mm) on each measurement surface and calculating the number of rays passing through each grid.

[0066] Next, in step 203, to identify the measurement surface where the light beam incident on the convex portion has the maximum density, the measurement surface P1,i with the first maximum density is identified from the predetermined distance among the measurement surfaces P1,1 to P1,n. To save calculations, the calculation of the light beam density may be started from the measurement surface P1, and after the first maximum value is detected, the calculation of this step may be terminated when the calculated value of the light beam density has decreased to approximately the intermediate value between the value at the measurement surface P1 and the first maximum value.

[0067] 7, in step 204, measurement surfaces P2,1 and P2,2 are set at positions spaced a distance Δd / 2 before and after measurement surface P1,i having the highest density. Then, in step 205, the light densities at measurement surfaces P2,1 and P2,2 are calculated. Next, in step 206, measurement surfaces P2,1, P2,2, and the measurement surface having the highest density among measurement surfaces P1,i are identified.

[0068] Thereafter, in step 207, steps similar to steps 204 to 206 are repeated until the separation distance becomes sufficiently small. That is, as shown in Fig. 8, the following steps are repeated: setting new measurement surfaces (P3,1 and P3,2 in Fig. 8) at positions before and after the measurement surface (P2,2 in Fig. 8) with the highest density immediately before, at a new separation distance that is half the previous separation distance (Δd / 4 in Fig. 8); calculating the density of light rays on the new measurement surfaces; and identifying the measurement surface with the highest density immediately before and the new measurement surface. These steps make it possible to identify the position at which the light rays are focused in the optical axis direction (lens thickness direction, Z axis).

[0069] Next, the convergence position of the light rays on a plane perpendicular to the optical axis direction (i.e., on the specified measurement surface) is identified. The PSF mentioned above is used for this identification. The point where the light rays (points on the measurement surface) are most densely concentrated according to the PSF is determined to be the convergence position B of the light rays on the measurement surface.

[0070] Then, the number of light rays on the measurement surface outside a range of, for example, a radius of 2.5 to 20 μm from the convergence position B of the light rays is calculated. In this specification, the range of, for example, a radius of 2.5 to 20 μm (a radius of 5.7 μm is used in this specification) from the convergence position B is defined as the "near position B."

[0071] Of the light rays outside the range, light rays within a radius of, for example, 2.5 to 20 μm from a predetermined position A where the light rays converge on the eyeglass lens itself (i.e., normal light rays that converge at position A) are subtracted. In this specification, the range of, for example, a radius of 2.5 to 20 μm (a radius of 5.7 μm is used in this specification) from the convergence position A is defined as the "near position A."

[0072] The subtracted number of light rays do not converge near position A where light rays converge at the spectacle lens 1 itself, nor do they converge near position B near the object side where light rays converge at the coating convex portion 11. In this specification, such light rays are referred to as stray light. By setting this stray light rate to 30% or less, it is possible to fully exert the myopia suppression effect even after forming a coating on the lens substrate 2.

[0073] The coating convex portion 11 preferably converges light rays incident on the eyeglass lens 1 to position B, which is closer to the object side than predetermined position A by a range of more than 0 mm and not more than 10 mm. In other words, the outermost surface of the eyeglass lens 1 in one embodiment of the present invention (i.e., the outermost surface of the coating) has a shape that converges light rays incident on the eyeglass lens 1 to position B, which is closer to the object side than predetermined position A by a range of more than 0 mm and not more than 10 mm. The range is preferably 0.1 to 7 mm, more preferably 0.1 to 5 mm, and even more preferably 0.3 to 3 mm.

[0074] The protruding distance L of the coating convex portion 11 ｃ and the protruding distance L of the base material protrusion 6. ｌ It is preferable that the relationship between the above and the above satisfies the following formula (1): 0.6≦L ｃ / L ｌ≦1.5 ... Equation (1) If this condition is satisfied, even if a coating is formed on the substrate convex portions 6, the coating convex portions 11 derived from the substrate convex portions 6 can move the convergence position B of the light rays incident on the eyeglass lens 1 sufficiently closer to the object side than the predetermined position A. This means that the coating convex portions 11, and therefore the eyeglass lens 1 of one aspect of the present invention, can exhibit a sufficient myopia suppression effect.

[0075] The protruding distance L of the coating convex portion 11 ｃ is the distance in the optical axis direction (lens thickness direction, Z axis) from the coating base portion of the outermost surface shape of the eyeglass lens 1 to the apex of the coating convex portion 11. ｌ is the distance in the optical axis direction (lens thickness direction, Z axis) from the substrate base portion of the lens substrate 2 to the apex of the substrate convex portion 6.

[0076] It is preferable that the half-width of the cross-sectional curve of astigmatism at the base of the coating convex portion 11 in the astigmatism distribution for the outermost surface shape of the coating is 0.20 mm or less.

[0077] In this specification, the "root (also referred to as the periphery) of a convex coating portion" refers to the boundary between the coating base portion and the convex coating portion on the outermost surface of the spectacle lens, the coating base portion in the vicinity thereof, and the portion where astigmatism begins to increase rapidly. Astigmatism (cross-sectional curve) in a cross-sectional view of a spectacle lens can be measured using a technique known as coherence correlation interferometry. Alternatively, the root of a convex coating portion may be defined as a substantially annular region that is 0.2 times the distance between the center and the boundary in a direction away from the center of the convex coating portion in a planar view.

[0078] Fig. 10 is a diagram showing a plot (solid line) of the astigmatism distribution (i.e., the astigmatism cross-sectional curve) in a cross section passing through the apex of the substrate convex portion 6 (i.e., the center of the substrate convex portion 6 in plan view) in the astigmatism distribution for the substrate convex portion 6 and its vicinity, which is a design value (i.e., without a coating). Fig. 11 is a diagram showing a plot (solid line) of the astigmatism distribution (i.e., the astigmatism cross-sectional curve) in a cross section passing through the apex of the coating convex portion 11 (i.e., the center of the coating convex portion in plan view) in the astigmatism distribution for the actual coating convex portion 11 and its vicinity.

[0079] 10 and 11, the horizontal axis indicates the X axis, i.e., the horizontal position when the object-side surface 3 of the eyeglass lens 1 is viewed in a plan view, and is measured in mm. Instead of the X axis, the Y axis, i.e., the vertical (top-bottom) direction when the object-side surface 3 of the eyeglass lens 1 is viewed in a plan view, may be used. The left vertical axis indicates the value of astigmatism (and average power) and is measured in diopters. The right vertical axis indicates the height of the coating convex portion 11 or the substrate convex portion 6 and is measured in mm. The coating convex portion 11 or the substrate convex portion 6 is the portion 0.3 to 1.3 mm on the horizontal axis. Also shown are a plot (dotted line) of the average power distribution (i.e., the cross-sectional curve of the average power distribution) and a plot (dashed line) of the Z-axis height of the coating convex portion 11 or the substrate convex portion 6.

[0080] 10, the astigmatism cross-sectional curve is designed to be substantially constant both in the base protrusion 6 and in the substantially horizontal base portion, and only the portion between the base protrusion 6 and the base portion has a shape that deviates from a spherical shape. Therefore, only this portion exhibits a high astigmatism value.

[0081] On the other hand, as shown in Fig. 11, the astigmatism cross section curve for the actual coating convex portion 11 and its vicinity shows that astigmatism increases over a relatively wide range in the X-axis direction between the coating convex portion 11 and the coating base portion (near X = 0.3 mm and X = 1.3 mm). This indicates that the shape between the coating convex portion 11 and the coating base portion deviates from the spherical shape over a relatively wide range compared to the design value shown in Fig. 10.

[0082] One cause of stray light rays is that the change in shape from the coating base portion at the base of the coating convex portion 11 is too gradual. In other words, if the coating base portion and the coating convex portion 11 are clearly separated, one cause of stray light rays can be eliminated, and ultimately, the myopia suppression effect can be fully exerted even after the coating is formed on the lens substrate 2. Therefore, the astigmatism section curve is used to show that there are not many parts with an incomplete shape between the coating base portion and the coating convex portion 11, which is one cause of stray light rays. In other words, the astigmatism section curve for the coating convex portion 11 defines the degree of change in shape at the base of the coating convex portion 11 (i.e., the gradient coating change).

[0083] The half-value width in Fig. 11 relating to an actual eyeglass lens is, as the name suggests, the peak width at half the value of the peak apex (diopter). For example, in Fig. 11, it is approximately 0.10 mm both near X = 0.3 mm and near X = 1.3 mm.

[0084] By specifying the half-value width of the astigmatism cross-sectional curve to be 0.20 mm or less, it is shown that there is a sudden change from the base portion to the coating convex portion 11, and therefore the eyeglass lens 1 of one embodiment of the present invention can exhibit a sufficient myopia suppression effect.

[0085] The coating preferably includes a λ / 4 film (not shown) in contact with the lens substrate 2, a hard coat film 8 formed on the λ / 4 film, and an anti-reflection film 10 formed on the hard coat film 8.

[0086] The λ / 4 film is not particularly limited as long as it has an optical thickness of λ / 4, and may be a film used in an anti-reflection filter, etc. As a specific example, a urethane resin (refractive index n=1.54) may be used as the λ / 4 film, and the thickness may be 70 to 90 nm.

[0087] There are no particular limitations on the hard coat film 8 as long as it improves the scratch resistance of the eyeglass lens 1. As a specific example, a metal-free silicon compound (refractive index n=1.50) may be used as the hard coat film 8, and the thickness may be 1.5 to 1.9 μm.

[0088] The anti-reflection film 10 may be a known one.

[0089] It is preferable that the refractive index of the lens substrate 2 is higher than that of the λ / 4 film, and that the refractive index of the λ / 4 film is higher than that of the hard coat film 8 .

[0090] Specific details other than those mentioned above will be described below.

[0091] [Lens Substrate 2] The size of the substrate protrusions 6 and the arrangement of the multiple substrate protrusions 6 on the surface of the lens substrate 2 are not particularly limited. There are no limitations on the substrate protrusions as long as they primarily function to cause a light beam incident from the object-side surface to exit from the eyeball-side surface and converge toward the object side (forward) of the retina. For example, they can be determined from the perspective of the visibility of the substrate protrusions 6 from outside, the design provided by the substrate protrusions 6, and the refractive power adjustment provided by the substrate protrusions 6. As described above, the size of the substrate protrusions is not limited, and they may have any size or shape that results in uneven distribution of the thickness of the coating formed at the base of the substrate protrusions. For example, they may be circular in plan view or spherical in three-dimensional shape. They may be elliptical in plan view or toric in three-dimensional shape. This also applies to the shape of the coating protrusions. FIG. 14( a ) is a diagram showing a case where the coating protrusions are arranged in a discrete arrangement (the center of each coating protrusion is located at the apex of the honeycomb structure) so that the center of each coating protrusion is the apex of an equilateral triangle in plan view, and FIG. 14( b ) is a diagram showing a case where the coating protrusions are arranged in a line in plan view. The dotted lines indicate an arbitrary circular area used when measuring the stray light rate (details will be described later). As described above, there are no limitations on the arrangement of the substrate protrusions. As shown in Example 1 and FIG. 14( a ) below, a discrete arrangement (the center of each substrate protrusion is located at the apex of the honeycomb structure) so that the center of each substrate protrusion is the apex of an equilateral triangle in plan view may also be employed. As shown in FIG. 14( b ) below, a structure where the substrate protrusions are arranged in a line in plan view may also be employed. Furthermore, a structure where the substrate protrusions are arranged in a line and another substrate protrusion is arranged adjacent to the line may also be employed. In this case, the pitch between the substrate protrusions in one row (the distance between the centers of the substrate protrusions, the same applies hereinafter) may be different from the pitch between the substrate protrusions in one row and the substrate protrusions in another row adjacent to the substrate protrusions. Furthermore, the spacing between the substrate protrusions in one row may be different from the spacing between adjacent rows. The height of the substrate protrusions 6 may be, for example, 0.1 to 10 μm, or 0.5 to 2 μm (corresponding to a refractive power of the substrate protrusions of 2.50 to 6.50 D). The upper limit of the refractive power of the substrate protrusions may be 5.50 D or 5.00 D, and the lower limit may be 3.00 D.The radius of curvature of the surface of the substrate protrusion 6 may be, for example, 50 to 250 mmR. Furthermore, the distance between adjacent substrate protrusions 6 (the distance between the end of a substrate protrusion 6 and the end of the substrate protrusion 6 adjacent to this substrate protrusion 6) may be, for example, approximately the same as the value of the radius of the substrate protrusion 6. Furthermore, multiple substrate protrusions 6 can be arranged approximately uniformly, for example, near the center of the lens. As shown in FIG. 10 of Patent Document 1, a substrate protrusion may be formed in the center of the eyeglass lens, or as shown in FIG. 1 of Patent Document 1, a substrate protrusion may not be formed in the center of the eyeglass lens.

[0092] The lens substrate 2 can be any of various lens substrates 2 commonly used for spectacle lenses 1. The lens substrate 2 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 2 from the viewpoints of 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 (commonly 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 2 may be undyed (colorless lenses) or dyed (dyed lenses). The thickness and diameter of the lens substrate 2 are not particularly limited, but the thickness (center thickness) may be approximately 1 to 30 mm, and the diameter may be approximately 50 to 100 mm, for example. The refractive index of the lens substrate 2 may be approximately 1.60 to 1.75, for example. However, the refractive index of the lens substrate 2 is not limited to the above range and may be within the above range or may deviate above or below the range. In this invention and this specification, the refractive index refers to the refractive index for light with a wavelength of 500 nm. The lens substrate 2 can be molded by known molding methods such as cast polymerization. For example, a lens substrate 2 having substrate convex portions 6 on at least one surface can be obtained by molding the lens substrate 2 by cast polymerization using a mold having a molding surface with multiple concave portions.

[0093] [Coating] One embodiment of the coating formed on the surface of the lens substrate 2 having the substrate convex portions 6 is a cured film formed by curing a curable composition containing a curable compound. Such a cured film is generally called a hard coat film 8, and contributes to improving the durability of the eyeglass lens 1. A curable compound refers to a compound having a curable functional group, and a curable composition refers to a composition containing one or more curable compounds.

[0094] One embodiment of the curable composition for forming the cured film includes a curable composition containing an organosilicon compound as the curable compound, and also includes a curable composition containing metal oxide particles together with the organosilicon compound. An example of the curable composition capable of forming the cured film is the curable composition described in JP-A-63-10640.

[0095] Furthermore, one embodiment of the organosilicon compound includes an organosilicon compound represented by the following general formula (I) and its hydrolyzate. (R １ ) ａ (R ３ ) ｂ Si(OR ２ ) ４－（ａ＋ｂ）　 ...(I)

[0096] In general formula (I), R １ represents an organic group having a glycidoxy group, an epoxy group, a vinyl group, a methacryloxy group, an acryloxy group, a mercapto group, an amino group, a phenyl group, or the like; R ２ represents an alkyl group having 1 to 4 carbon atoms, an acyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R ３ represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms; a and b each represent 0 or 1.

[0097] R ２ The alkyl group having 1 to 4 carbon atoms represented by the formula (R) is a linear or branched alkyl group, and specific examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. ２ Examples of the acyl group having 1 to 4 carbon atoms represented by R include an acetyl group, a propionyl group, an oleyl group, and a benzoyl group.２ Examples of the aryl group having 6 to 10 carbon atoms represented by R include a phenyl group, a xylyl group, and a tolyl group. ３ The alkyl group having 1 to 6 carbon atoms represented by the formula (R) is a linear or branched alkyl group, and specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. ３ Examples of the aryl group having 6 to 10 carbon atoms represented by the formula (I) include a phenyl group, a xylyl group, and a tolyl group. Specific examples of the compound represented by the formula (I) include the compounds described in paragraph 0073 of JP-A-2007-077327. Because the organosilicon compound represented by the formula (I) has a curable group, it can be subjected to a curing treatment after application to form a hard coat film 8 as a cured film.

[0098] The metal oxide particles can contribute to adjusting the refractive index of the cured film and improving the hardness. Specific examples of the metal oxide particles include tungsten oxide (WO ３ ), zinc oxide (ZnO), silicon oxide (SiO ２ ), aluminum oxide (Al ２ O ３ ), titanium oxide (TiO ２ ), zirconium oxide (ZrO ２ ), tin oxide (SnO ２ ), beryllium oxide (BeO), antimony oxide (Sb ２ O ５ ) and the like, which can be used alone or in combination of two or more types of metal oxide particles. The particle size of the metal oxide particles is preferably in the range of 5 to 30 nm from the viewpoint of achieving both scratch resistance and optical properties of the cured film. The content of the metal oxide particles in the curable composition can be appropriately set taking into consideration the refractive index and hardness of the cured film to be formed, and may typically be about 5 to 80 mass% based on the solid content of the curable composition. Furthermore, the metal oxide particles are preferably colloidal particles from the viewpoint of dispersibility in the cured film.

[0099] The cured film can be formed, for example, by directly applying a curable composition prepared by mixing the above components and, if necessary, optional components such as an organic solvent, a surfactant (leveling agent), and a curing agent to the surface of the lens substrate 2 having the substrate convex portions 6, or indirectly applying the composition via another film to form a coating film, and then subjecting this coating film to a curing treatment (e.g., heating and / or light irradiation) appropriate for the type of curable compound. Details of the application of the curable composition will be described later. For example, when the curing treatment is performed by heating, the lens substrate 2 on which the coating film of the curable composition has been formed can be placed in an environment with an ambient temperature of 50 to 150°C for approximately 30 minutes to 2 hours, thereby allowing the curing reaction of the curable compound in the coating film to proceed.

[0100] From the viewpoint of suitability for application by spin coating, the viscosity of the curable composition for forming a coating on the surface of the lens substrate 2 having the substrate convex portions 6 is preferably in the range of 1 to 50 mPa s, more preferably in the range of 1 to 40 mPa s, and even more preferably in the range of 1 to 20 mPa s. In the present invention and this specification, viscosity refers to viscosity at a liquid temperature of 25°C.

[0101] Another example of a coating formed on the surface of the lens substrate 2 having the substrate convex portions 6 is a coating generally called a primer film, which contributes to improving adhesion between layers. Examples of coating solutions capable of forming such coatings include compositions in which a resin component such as a polyurethane resin is dispersed in a solvent (water, an organic solvent, or a mixture thereof) (hereinafter referred to as a "drying and solidifying composition"). Such compositions solidify when the solvent is dried and removed. Drying can be performed by a drying process such as air drying or heat drying.

[0102] From the viewpoint of suitability for application by spin coating, the viscosity of the drying / solidifying composition for forming a coating on the surface of the lens substrate 2 having the substrate convex portions 6 is preferably in the range of 1 to 50 mPa s, more preferably in the range of 1 to 40 mPa s, and even more preferably in the range of 1 to 20 mPa s.

[0103] [Supply of Coating Liquid] The coating liquid for forming a coating on the surface of the lens substrate 2 having the substrate convex portions 6 is supplied by spin coating. By performing the coating by spin coating, it is possible to prevent the coating from becoming non-uniform in thickness, which may be caused by liquid pooling around the substrate convex portions 6. Application by spin coating can be performed, for example, by placing the lens substrate 2 on a spin coater with the surface having the substrate convex portions 6 facing vertically upward, and supplying the coating liquid onto the surface from above while rotating the lens substrate 2 on the spin coater (for example, by ejecting the coating liquid from a nozzle disposed above the surface). Here, the rotation speed of the lens substrate 2 during spin coating is preferably in the range of 10 to 3000 rpm (rotations per minute), more preferably in the range of 50 to 2500 rpm, and even more preferably in the range of 100 to 2000 rpm, from the viewpoint of forming a coating with a more uniform thickness. However, the present invention is not limited to the spin coating method, and may be realized by using a known method (for example, a dipping method).

[0104] After the application, a coating can be formed by carrying out a treatment (for example, a curing treatment, a drying treatment, etc.) depending on the type of the coating liquid.

[0105] The thickness of the coating formed through the above steps may be, for example, in the range of 0.5 to 100 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. The height of the coating convex portion may be, for example, 0.1 to 10 μm, similar to the substrate protrusion, and preferably 0.5 to 2 μm. The defocus power of the coating convex portion may also be, similar to the substrate protrusion, a refractive power of 2.50 to 6.50 D. The upper limit of the defocus power may be 5.50 D or 5.00 D, and the lower limit may be 3.00 D. In this specification, "defocus power" refers to the difference between the refractive power of each defocus region and the refractive power of the portion other than each defocus region. In other words, "defocus power" is the difference obtained by subtracting the refractive power of the base portion from the average value of the minimum and maximum refractive powers at a predetermined location in the defocus region. In this specification, a case where the defocus region is a convex region is exemplified. In this specification, "refractive power" refers to the average refractive power, which is the average value of the refractive power in direction a where the refractive power is minimum and the refractive power in direction b (perpendicular to direction a) where the refractive power is maximum.

[0106] One or more additional coatings can be formed on the coating. Examples of such coatings include various coatings such as an anti-reflection coating 10, a water-repellent or hydrophilic anti-fouling coating, and an anti-fogging coating. Known techniques can be applied to the formation of these coatings. Furthermore, when one surface of the lens substrate 2 does not have substrate convex portions 6, one or more coatings can also be formed on the surface of such a lens substrate 2. Examples of such coatings include various coatings that are typically provided on eyeglass lenses 1 (e.g., a hard coat film 8, a primer film, an anti-reflection coating 10, an anti-fouling coating, an anti-fogging coating, etc.), and known techniques can be applied to the formation of these coatings.

[0107] In the above-described aspect of the present invention, the maximum absolute value of the difference in the lens thickness direction between the spherical surface optimally approximated to the shape of the coating convex portion 11 and the actual shape of the coating convex portion 11 was set to 0.1 μm or less. However, the spectacle lens 1 according to the present invention is not limited to this definition of difference. In short, the gist of the present invention is that the convex portion on the outermost surface of the spectacle lens 1 on the side having the substrate convex portion 6 converges light rays incident on the spectacle lens 1 to position B closer to the object side than predetermined position A, even after the coating has been formed, and this gist is novel.

[0108] In addition to or instead of the above-described provisions for the spectacle lens of one aspect of the present invention, the following provisions may be used: Of the many light rays obtained by ray tracing calculations that are uniformly incident within a predetermined range on the object-side surface of the spectacle lens and pass through the coating, the number of stray light rays that do not pass near a predetermined position A and do not pass near a position B closer to the object side is set to 30% or less of the number of incident light rays. In other words, the spectacle lens has the following configuration: "A spectacle lens that causes light rays incident from the object-side surface to exit from the eyeball-side surface and converge at a predetermined position A, the spectacle lens comprising a lens substrate having a plurality of substrate convex portions on at least one of the object-side surface and the eyeball-side surface, and having a configuration that suppresses the generation of stray light rays that do not pass near the predetermined position A and do not pass near a position B closer to the object side than the predetermined position A."

[0109] In this another embodiment, a coating was described. However, while coatings were indeed considered when developing the present invention, the coatings were merely one of the factors that led to the development of the present invention. Therefore, this another embodiment is not limited to eyeglass lenses 1 that include a coating. In short, in this another embodiment, the presence or absence of a coating is not important as long as the configuration suppresses the generation of stray light rays that do not pass near predetermined position A and do not pass near position B, which is closer to the object side than predetermined position A. For example, even if the lens substrate 2 does not include a coating, stray light rays may be generated depending on the shape of the substrate convex portion 6 of the lens substrate 2. In such cases, it is technically significant to employ a configuration for suppressing the generation of stray light rays in the eyeglass lens 1. Furthermore, the "configuration for suppressing the generation of stray light rays" may relate to the shape of the object-side surface 3 or the eyeball-side surface 4 of the eyeglass lens 1, or may relate to the composition of the lens substrate 2 or the coating.

[0110] In addition to or instead of the above-described specification for the spectacle lens of one aspect of the present invention, the following specification may be used: In another aspect, the maximum absolute value of the difference in the lens thickness direction between the actual coating convex portion shape and the actual substrate convex portion shape is 0.1 μm or less (preferably 0.06 μm or less).

[0111] The advantages of defining the difference will be explained below.

[0112] No matter how a coating is formed on the lens substrate 2 and the coating convex portion 11 has a blunter shape than the substrate convex portion 6, at least the apex portion of the coating convex portion 11 has a shape that follows the substrate convex portion 6.

[0113] That is, in this other aspect, the approximate partial spherical shape of the actual coating convex portion 11 is compared with the partial spherical shape of the actual lens substrate 2 .

[0114] Fig. 12(a) is a schematic cross-sectional view showing the coating convex portions 11 and the substrate convex portions 6 of an actual eyeglass lens 1. Fig. 12(b) is a schematic cross-sectional view in which the apex of the coating convex portions 11 and the apex of the substrate convex portions 6 are aligned. The solid lines indicate the coating convex portions 11 of the actual eyeglass lens 1, the dashed lines indicate the substrate convex portions 6, and the vertical lines indicate the difference in the lens thickness direction between the coating convex portion shape and the substrate convex portion shape.

[0115] In Figure 12 (b), the apex of the coating convex portion 11 and the apex of the substrate convex portion 6 are aligned, and the difference in the lens thickness direction (optical axis direction) between the actual substrate convex portion 6 from the shape of the base portion of the substrate convex portion 6, from the point where it starts to rise and moves towards the apex to the point where it ends, and the coating convex portion 11 of the actual eyeglass lens 1 is examined.

[0116] If the maximum absolute value of this difference is 0.1 μm or less (preferably 0.06 μm or less), it is considered that the coating can faithfully follow the shape of the substrate convex portions 6 present underneath. As a result, it has been found that the myopia suppression effect can be fully exerted. By applying this regulation, the myopia suppression effect can be fully exerted. It is also possible to specify the similarity rate between the shape of the coating convex portions 11 and the shape of the substrate convex portions 6.

[0117] Furthermore, in addition to or instead of the above-mentioned definition of the spectacle lens of one aspect of the present invention, the following definition may be used: "A spectacle lens that causes light rays incident on an object-side surface to exit from an eyeball-side surface and converge at a predetermined position A, the spectacle lens comprising: a lens substrate having a plurality of substrate convex portions on at least one of the object-side surface and the eyeball-side surface; and a coating covering the surface having the substrate convex portions, the coating having a thickness of 3.0 μm or less."

[0118] Furthermore, in addition to or instead of the definition of the spectacle lens according to one aspect of the present invention described above, the following definition may be used: "A spectacle lens that causes light rays incident on an object-side surface to exit from an eyeball-side surface and converge at a predetermined position A, the spectacle lens comprising: a lens substrate having a plurality of substrate convex portions on at least one of the object-side surface and the eyeball-side surface; and a coating covering the surface having the substrate convex portions, wherein the convex portions on the outermost surface of the spectacle lens on the side having the substrate convex portions and the substrate convex portions have a common light convergence characteristic."

[0119] In this another aspect, the maximum absolute value of the difference in the lens thickness direction between the shape of the actual coating convex portion 11 and the shape of the actual substrate convex portion 6 is set to 0.1 μm or less. However, the spectacle lens 1 according to this another aspect is not limited to this difference. In short, the gist of this another aspect is that the convex portion on the outermost surface of the spectacle lens 1 on the side having the substrate convex portion 6 and the substrate convex portion 6 have a common light beam convergence characteristic, and this gist is novel. The "common light beam convergence characteristic" refers to the characteristic of converging light rays closer to the object side than a predetermined position A at which light rays are converged by the base portion of the spectacle lens. The shape of the convex portion on the outermost surface of the spectacle lens 1 on the side having the substrate convex portion 6 follows the shape of the substrate convex portion 6, and therefore the common light beam convergence characteristic is achieved. There is no particular limitation on the distance closer to the object side than the predetermined position A. For example, the position where the light rays are converged by the convex portion on the outermost surface of the eyeglass lens 1 on the side having the substrate convex portion 6 and the position where the light rays are converged by the substrate convex portion 6 may be set within the above-mentioned range from the predetermined position A, i.e., within a range exceeding 0 mm and not exceeding 10 mm.

[0120] In this other embodiment, the difference in the lens thickness direction between the shape of the coating convex portion 11 and the shape of the substrate convex portion 6 is specified. However, in the spectacle lens 1 according to this other embodiment, the thickness of the coating itself may be specified rather than specifying this difference. When a coating is formed on a lens substrate 2 having substrate convex portions 6 that exhibit a myopia suppression effect, if the coating is too thick, the substrate convex portions 6 will be buried in the coating, and the difference between the coating base portion and the coating convex portions 11 will disappear. However, if the coating thickness is 3.0 μm or less (preferably 2.0 μm or less), the shape of the coating convex portions 11 will follow the shape of the substrate convex portions 6 well. This specification, like the "common light convergence characteristic," is a specification that can increase similarity. Furthermore, the provision that "the thickness of the coating is 3.0 μm or less (preferably 2.0 μm or less)" is based on the technical idea that "the coating convex portions faithfully follow the shape of the substrate convex portions in the lens substrate," similar to the difference in the lens thickness direction between the shape of the coating convex portions 11 and the shape of the substrate convex portions 6.

[0121] The technical concept of the spectacle lens of one aspect of the present invention described above can also be applied to spectacle lenses that exhibit a hyperopia suppression function. Specifically, the "convex portions" of the coating convex portion 11 and the substrate convex portion 6 are changed to "concave portions." As a result, the coating concave portions converge light rays that have entered the spectacle lens to position B', which is closer to the "eyeball side" than predetermined position A. In the spectacle lens of one aspect of the present invention described above, if the "convex portions" are changed to "concave portions" and the light rays are changed so as to converge to position B', which is closer to the "eyeball side" than predetermined position A, the spectacle lens will exhibit a hyperopia suppression function.

[0122] The present invention will now be described in more detail with reference to examples, although the present invention is not limited to the following examples.

[0123] Example 1 The following lens substrate was produced. No other substance was laminated onto the lens substrate. The prescription power was S (spherical power) 0.00D and C (cylindrical power) 0.00D. Diameter of lens substrate in plan view: 100 mm Type of lens substrate: PC (polycarbonate) Refractive index of lens substrate: 1.589 Base curve of lens substrate: 3.30D Surface on which substrate convex portions are formed: Object-side surface Shape of substrate convex portions in plan view: Perfect circle (diameter 1 mm) Height of substrate convex portions from substrate base portion: 0.8 mm Arrangement of substrate convex portions in plan view: Independently and discretely arranged so that the center of each substrate convex portion is the apex of an equilateral triangle (the center of each substrate convex portion is located at the apex of the honeycomb structure) Area in which substrate convex portions are formed: Within a circle with a radius of 17 mm from the center of the lens Pitch between substrate convex portions (distance between the centers of substrate convex portions): 1.5 mm

[0124] A coating was formed on both sides of this lens substrate by spin coating. The conditions for the spin coating were as follows: Coating liquid: thermosetting coating agent, Rotation speed: 1300 rpm, Drying method after spin coating: heating, Drying temperature after spin coating: 110°C, Drying time after spin coating: 90 min.

[0125] <Comparative Example 1> The conditions for the spin coating method were as follows. The rest were the same as in Example 1. Coating liquid: thermosetting coating agent Rotation speed: 800 rpm Drying method after spin coating: heating Drying temperature after spin coating: 110°C Drying time after spin coating: 90 min

[0126] <Measurement of Defocus Power and Stray Light Rate> The defocus power was measured for Example 1 and Comparative Example 1. The defocus power (unit: D) ​​is a value indicating the distance from the retina at which a light beam is focused, and can be measured by ray tracing and by using some of the above-mentioned stray light rate measurement techniques.

[0127] The stray light ratio was measured using the above-described method for Example 1 and Comparative Example 1. The stray light ratio is expressed as 100×(number of stray light rays) / (number of incident light rays).

[0128] The measurement results of the defocus power and stray light rate were obtained as follows. Within the range where the substrate convex portions were formed (within a circle with a radius of 17 mm from the center of the lens), an arbitrary circular region including all seven of the coating convex portions was imagined, and the values ​​in this circular region were used as the measurement results. Using the above-mentioned method, a glasses model and an eyeball model were set up, and a large number of light rays were incident on the circular region using ray tracing to identify the focusing position.

[0129] The eyeball model and various other conditions are as follows: Axial length: 24 mm Amount of accommodation: 0.0 D Cornea-lens vertex distance (CVD): 12.0 mm Distance from the corneal vertex to the center of rotation of the eyeball: 13.0 mm Hereinafter, unless otherwise specified, the above conditions will be used. However, the present invention is not limited to the above conditions. For example, in the above example, an arbitrary circular region including seven entire coating convexities, as shown in FIG. 14( a), was assumed. On the other hand, a circular region including three entire coating convexities lined up in a row, as shown in FIG. 14( b), may also be used. This circular region may be, for example, a circular region centered on one coating convexity (and thus a substrate protrusion) and including another coating convexity that is the shortest distance from that coating convexity. In this specification, this circular region is also referred to as the "minimum unit." In Figure 14(a), there are six other coating convex portions, and in Figure 14(b), there are two other coating convex portions. This circular region may correspond to the diameter of a lens meter (PSF analysis range). Typically, the diameter of a lens meter is 4.0 mm. If the pitch between coating convex portions (between substrate protrusions) is approximately the same as the diameter of the lens meter (e.g., 4.0 mm), one coating convex portion may be present in the circular region, and this may be used as the smallest unit. The "stray light ratio" in this specification is a result obtained by measuring the smallest unit. In other words, the "stray light ratio" in this specification is a result obtained by measuring the smallest unit, which is a circular region (e.g., 4.0 mm in diameter) centered on one coating convex portion (and thus a substrate protrusion) and including the entire other coating convex portion located at the shortest distance from that coating convex portion. The spectacle lenses in this specification have multiple such smallest units. The effects of the present invention can be achieved if the stray light ratio of at least one of the minimum units of the spectacle lens satisfies the above-mentioned numerical range. In order of suitability, it is preferable that the number of minimum units exceeding 50%, 80% or more, 90% or more, and 95% or more of the minimum units satisfy the above-mentioned stray light ratio specification.

[0130] First, eyeglass models using multiple design shapes were created, and the focusing position was investigated using the method described in the "Description of Embodiments." The convex surface of the design eyeglass model (lens substrate) here was a spherical substrate base portion, and the substrate convex portion was composed of a spherical surface with a radius of curvature smaller than that of the substrate base portion. Multiple design shapes were created by discretely changing the radius of curvature of the substrate convex portion relative to the spherical substrate base portion, which had a constant curvature. The defocus value was calculated by subtracting the surface refractive power [D] due to the radius of curvature of the substrate base portion from the surface refractive power [D] due to the radius of curvature of the substrate convex portion. A correlation equation between this defocus value and the defocus power calculated from the reciprocal of the actual focusing position was obtained by ray tracing performed on eyeglass models using multiple design shapes.

[0131] FIG. 13 is a plot showing the correlation between the value (defocus value) (horizontal axis) obtained by subtracting the surface refractive power of the substrate base portion from the surface refractive power of the substrate convex portion, and the defocus power (vertical axis) calculated from the reciprocal of the focusing position.

[0132] The measurement of the defocus power in Example 1 was carried out by using this correlation formula to determine a value equivalent to the defocus power in the spectacle lens produced in Example 1.

[0133] The stray light rate was also calculated from the PSF of the light collection position determined by the method described in the embodiment of the present invention.

[0134] In Example 1 and Comparative Example 1, it is assumed that there are seven regions where light rays are densely concentrated on a plane perpendicular to the optical axis direction at the focusing position (optical axis direction) determined during the defocus power measurement. This is because an arbitrary circular region including seven entire coating convex portions is assumed. A lattice-like grid is set on each measurement surface, the number of light rays passing through each grid is calculated, and the grids with a certain number or more are examined, and it is assumed that light rays are densely distributed in seven regions.

[0135] In Example 1 and Comparative Example 1, the center of gravity positions of these regions were determined as multiple convergence positions B, and the number of stray light rays was determined by subtracting the light rays near position A from the light rays outside the range near position B. From this number of stray light rays, the stray light rate was calculated using the method described in [Mode for Carrying Out the Invention].

[0136] The spectacle lens of Example 1 had a lower stray light rate than the spectacle lens of Comparative Example 1. Specifically, the spectacle lens of Example 1 had a defocus power of 3.51 D and a stray light rate of 11.25%, both of which were 30% or less, whereas the spectacle lens of Comparative Example 1 did not meet these conditions. Furthermore, the spectacle lens of Example 1 was able to ensure a sufficient defocus power compared to the spectacle lens of Comparative Example 1.

[0137] <Cross-sectional curve of astigmatism at the base of the coating convex portion> A cross-sectional curve of astigmatism at the base of the coating convex portion in the astigmatism distribution for the outermost surface shape of the coating was obtained for Example 1. The cross-sectional curve can be measured by a technique known as coherence correlation interferometry.

[0138] The results of Example 1 are shown in FIG.

[0139] In FIG. 11 relating to Example 1, the cross-sectional curve of astigmatism at the base of the coating convex portion in the astigmatism distribution for the outermost surface shape of the coating is 0.20 mm or less, whereas in Comparative Example 1, this condition was not met.

[0140] REFERENCE SIGNS LIST 1 Spectacle lens 2 Lens substrate 3 Object-side surface (convex surface) 4 Eyeball-side surface (concave surface) 6 Substrate convex portion 8 Hard coat film 10 Anti-reflection film 11 Coating convex portion 20 Eyeball 20A Retina 30 Spectacle lens model 32 Eyeball model 32A Retina 33 Object-side surface on model (convex surface) 36 Coating convex portion on model

Claims

1. A spectacle lens that causes light rays incident on the object-side surface to exit from the eyeball-side surface and converge at a predetermined position A, comprising: a lens substrate having a plurality of substrate convex portions on at least one of the object-side surface and the eyeball-side surface; and a coating that covers the surface having the substrate convex portions, wherein the shape of the coating convex portions on the outermost surface of the spectacle lens on the side having the substrate convex portions is an approximation of the shape of the substrate convex portions that causes light rays incident on the spectacle lens to converge at position B, which is closer to the object side than the predetermined position A.

2. The eyeglass lens according to claim 1, wherein, among the numerous light rays that are evenly incident within a predetermined range on the object-side surface of the eyeglass lens and pass through the coating, the number of stray light rays that do not pass near the predetermined position A and that do not pass near the position B closer to the object side, obtained by ray tracing calculation, is 30% or less of the number of incident light rays.

3. The spectacle lens according to claim 1 or 2, wherein the profile curve of astigmatism at the base of the convex portion of the coating in the astigmatism distribution for the outermost surface shape of the coating is 0.20 mm or less.

4. A spectacle lens according to any one of claims 1 to 3, wherein the maximum absolute value of the difference in the lens thickness direction between the spherical surface optimally approximated to the coating convex portion shape and the actual coating convex portion shape is 0.1 μm or less.

5. Projection distance L of the coating convex portion ｃ and the protruding distance L of the base material convex portion. ｌ The eyeglass lens according to any one of claims 1 to 4, wherein the relationship between L and L satisfies the following formula (1): 0.6≦L ｃ / L ｌ ≦1.5...Formula (1)