Spectacle lens

Abstract

Provided is a spectacle lens having a center clear region including an eye point and achieving prescription refractive power of a wearer, and an annular functional region surrounding the center clear region, the functional region having a base region for achieving prescription refractive power, and a plurality of defocus regions having a refractive power different from the prescription refractive power, and the plurality of defocus regions being arranged side by side in an X direction and in a Y direction intersecting the X direction at a predetermined angle in a plan view, and when a convex polygon is assumed which exists in a boundary portion between the center clear region and the functional region in a plan view and which has as a side thereof a virtual line passing through the centers of two or more defocus regions, the centers of the defocus regions not being present inside the convex polygon, and the area of the convex polygon being maximized, the maximum value of the external angles of the convex polygon is 36 degrees or less.

Description

eyeglass lenses

[0001] The present invention relates to eyeglass lenses.

[0002] As one form of spectacle lens that has the effect of inhibiting the progression of myopia or reducing hyperopia, for example, Patent Document 1 describes a spectacle lens that has a clear area and a functional area.

[0003] Patent No. 7177959

[0004] An object of one embodiment of the present invention is to provide a technique for reducing the overlapping image caused by blurring at the boundary between the central clear area and the functional area.

[0005] A first aspect of the present invention is a spectacle lens having: a central clear area that realizes the prescribed refractive power of a wearer and includes an eye point; and an annular functional area that surrounds the central clear area, wherein the functional area has a base area that realizes the prescribed refractive power and a plurality of defocus areas having a refractive power different from the prescribed refractive power, wherein, in a planar view, the plurality of defocus areas are arranged side by side in an X direction and a Y direction that intersects with the X direction at a predetermined angle, and wherein, when a convex polygon is formed on the boundary between the central clear area and the functional area in a planar view and has sides that are virtual lines passing through the centers of two or more of the defocus areas, the center of the defocus area does not exist inside the convex polygon and when the area of ​​the convex polygon is maximized, the maximum value of the exterior angle of the convex polygon is 36 degrees or less.

[0006] A second aspect of the present invention is the spectacle lens according to the first aspect, wherein the diameter of the defocus area is 0.5 mm or more and 2.5 mm or less.

[0007] A third aspect of the present invention is the eyeglass lens according to the first aspect, wherein the distance r from the center of the convex polygon to the center of the nearest defocus area is four times or more the center-to-center distance p of adjacent defocus areas.

[0008] A fourth aspect of the present invention is the eyeglass lens according to the first aspect, wherein the distance r from the center of the convex polygon to the center of the nearest defocus area is 5 times or less the center-to-center distance p of adjacent defocus areas.

[0009] A fifth aspect of the present invention is the spectacle lens according to the first aspect, wherein a distance r from the center of the convex polygon to the center of the closest defocus area is 5.5 mm or more and 10 mm or less.

[0010] A sixth aspect of the present invention is the spectacle lens according to any one of the first to fifth aspects, which has the effect of inhibiting the progression of myopia or reducing hyperopia.

[0011] According to one embodiment of the present invention, it is possible to reduce the overlapping image caused by blurring at the boundary between the central clear area and the functional area.

[0012] FIG. 1A is an enlarged schematic plan view of the vicinity of the eyepoint of a spectacle lens according to a reference example that exhibits a myopia progression suppression effect, in which the defocus regions are arranged in a concentric circular pattern. FIG. 1B is an enlarged schematic plan view of the vicinity of the eyepoint of a spectacle lens according to a reference example that exhibits a myopia progression suppression effect, in which the defocus regions are arranged in a Cartesian coordinate system pattern. FIG. 2 is a diagram showing the results of a simulation of how an original image appears blurred when the angle formed by adjacent boundaries at the boundary between the central clear region and the functional region is changed in a spectacle lens having defocus regions with a pitch of 1.5 mm, a diameter of 1 mm, and a height of 1 μm. FIG. 3 is an enlarged schematic plan view of the vicinity of the eyepoint of a spectacle lens according to a reference example that exhibits a myopia progression suppression effect. FIG. 4 is a schematic plan view of the object-side surface of a spectacle lens according to an embodiment of the present invention. FIG. 5 is an enlarged schematic plan view of the vicinity of the eyepoint of a spectacle lens according to an embodiment of the present invention. FIG. 6 is an enlarged schematic plan view of the vicinity of the eyepoint of spectacle lenses of Samples 1 to 5 according to examples of the present invention. FIG. 7 is a diagram showing the results of a simulation of how the original image appears blurred when the line of sight is shifted 2 mm along the side of a convex polygon from the defocus region indicated by the arrow in FIG. 6 in the eyeglass lenses of Samples 1 to 5 according to the embodiment of the present invention.

[0013] <Discovery Obtained by the Inventor> First, the discovery obtained by the inventor will be described. FIGS. 1A and 1B are enlarged planar schematic diagrams of the vicinity of the eye point of a spectacle lens according to a reference example that exhibits the effect of inhibiting the progression of myopia. As shown in FIGS. 1A and 1B, the spectacle lens that exhibits the effect of inhibiting the progression of myopia has, for example, a central clear region 110 that realizes the prescribed refractive power of the wearer and includes the eye point, and an annular functional region 120 that surrounds the central clear region 110. The functional region 120 has a base region 130 that realizes the prescribed refractive power and multiple defocus regions 140 (also referred to as convex regions) that have a refractive power different from the prescribed refractive power. This configuration allows the spectacle lens to exhibit the effect of inhibiting the progression of myopia. Details of each region will be described later.

[0014] In general spectacle lenses that have the effect of suppressing the progression of myopia, there are roughly two types of arrangement of the multiple defocus regions 140. That is, there is a concentric type in which the defocus regions 140 are arranged concentrically as shown in Fig. 1A, and a Cartesian coordinate system / oblique coordinate system type (for simplicity, also referred to as a Cartesian coordinate system type) in which the defocus regions 140 are arranged side by side at equal intervals in the X direction and in the Y direction that intersects with the X direction at a predetermined angle as shown in Fig. 1B.

[0015] In a concentric circle type eyeglass lens, the arrangement period of the defocus areas 140 varies depending on the location of the functional area 120, and the arrangement pattern differs, which has the disadvantage of low uniformity of the optical characteristics of the functional area 120. For example, it can be seen that the arrangement patterns of the defocus areas 140 are different between areas Z1 and Z2 shown in Figure 1A. On the other hand, in a Cartesian coordinate system type eyeglass lens, the defocus areas 140 are arranged in the same direction and at equal intervals, so the same optical characteristics can be obtained over substantially the entire functional area 120.

[0016] However, the inventors' investigations revealed that Cartesian coordinate system type eyeglass lenses have a problem in that they are prone to causing discomfort due to blurring that lingers perpendicular to the boundary line at the boundary between the central clear area 110 and the functional area 120. For example, in area Z3 shown in Figure 1B, blurring occurs downward on the page, and in area Z4, blurring occurs downward and to the right on the page. When these blurrings are combined in binocular vision, for example, the viewer perceives multiple blurs as if the images are overlapping. This is hereinafter referred to as image overlapping.

[0017] The inventors conducted extensive research into the above-mentioned problem. The multiple blurring and image overlapping sensations are attributed to the large change in the direction of the blurring that lingers perpendicular to the boundary line at the boundary between the central clear area 110 and the functional area 120. For example, in the eyeglass lens shown in FIG. 1B , the boundary line is hexagonal, so the direction of the blur changes by approximately 60 degrees. The inventors therefore considered that the image overlapping sensation could be reduced by modifying the design of the boundary line so that the direction of the blur changes by only a smaller angle. FIG. 2 shows the results of a simulation of how the original image (upper left of FIG. 2 ) appears blurred when the angle between adjacent boundary lines at the boundary line is changed for an eyeglass lens with a defocus area 140 pitch of 1.5 mm, a diameter of 1 mm, and a height of 1 μm. A test was then conducted in which a large number of subjects were presented with the image shown in FIG. 2 and asked to compare their perceptions. The results showed that the majority of subjects were less likely to experience image overlapping when the angle of change in the direction of the adjacent boundary lines at the boundary line (i.e., the change in the direction of the blur) was 36 degrees or less.

[0018] 3 is an enlarged schematic plan view of the vicinity of the eyepoint of a spectacle lens according to a reference example that exhibits the effect of inhibiting the progression of myopia. As shown in FIG. 3, the direction of blur is perpendicular to the sides (the direction of the arrows in FIG. 2 ) of a convex polygon 200 (a hexagon in FIG. 2 ) formed by connecting the centers of defocus regions 140 present at the boundary between the central clear region 110 and the functional region 120 with imaginary lines. Note that, in this specification, when imaginary lines passing through the centers of two or more defocus regions 140 are used as the sides of the convex polygon 200, and the centers of the defocus regions 140 are not located within the convex polygon 200, and the area of ​​the convex polygon 200 is maximized. The inventor discovered that by increasing the number of vertices of this convex polygon 200 and designing it so that the maximum value of the exterior angle of the convex polygon 200 is 36 degrees or less, it is possible to realize a spectacle lens that is less likely to cause overlapping images at the boundary between the central clear area 110 and the functional area 120, even if the arrangement of the defocus area 140 is of the Cartesian coordinate system type.

[0019] To reduce the outer angle of the convex polygon 200, i.e., to draw a convex polygon 200 that is closer to a circle (having more vertices), it is necessary to reduce the diameter of the defocus regions 140 and the spacing between adjacent defocus regions 140, or to increase the size of the central clear region 110, so that the boundary is composed of many defocus regions 140. However, if the diameter of the defocus regions 140 is too small or the central clear region 110 is too large, the myopia progression suppression effect may not be fully achieved. Therefore, it is preferable to slightly enlarge the central clear region 110 from the conventional design (where the boundary portion is hexagonal) shown in FIG. 3 and set the maximum outer angle of the convex polygon 200 to 36 degrees or less. If the central clear region 110 is slightly enlarged (e.g., by about 20% from the conventional design), the apparent central clear region 110 can be adjusted by slightly moving the eyeglass lens away from the eye during fitting.

[0020] [Details of the embodiment of the present invention] Next, an embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0021] 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.

[0022] In this specification, the eyepoint is, for example, the position through which the line of sight passes when wearing eyeglasses and looking straight ahead, and this example will be given hereinafter. The eyepoint may also be the position through which the line of sight passes when the wearer views an object close to the wearer (i.e., when viewing close up), i.e., the near eyepoint. In one aspect of the present invention, an example is given in which the geometric center of the eyeglass lens before framing coincides with the eyepoint, coincides with the prism reference point, and coincides with the lens center. The eyepoint can be identified by referring to a remark chart or centration chart issued by the lens manufacturer.

[0023] <First embodiment of the present invention> (1) Eyeglasses and eyeglass lens Fig. 4 is a plan view schematic diagram of the object-side surface of eyeglass lens 10 of this embodiment. As shown in Fig. 4, eyeglass lens 10 of this embodiment is a myopia progression suppression lens that has the effect of suppressing the progression of myopia, and has a central clear area 11, a functional area 12, and a peripheral clear area 15.

[0024] The central clear area 11 is an area that realizes the prescribed refractive power of the wearer and includes the eye point of the eyeglass lens 10. In this embodiment, an example is shown in which the center of the central clear area 11 coincides with the eye point of the eyeglass lens 10. The central clear area 11 is, for example, a transparent part having a smooth surface shape, and is an area that causes a light beam that has entered from the surface on the object side to exit from the surface on the eyeball side, enter the pupil of the wearer, and converge on the retina.

[0025] The prescribed power (spherical power, astigmatic power, astigmatic axis, etc.) can be achieved by the central clear region 11. This spherical power may be a power (distance power) to be corrected when viewing straight ahead (when the distance to an object is from infinity to about 1 m), or may be a power to be corrected when viewing at intermediate distances (when the distance to an object is from about 1 m to 40 cm) or near distances (when the distance to an object is from about 40 cm to 10 cm).

[0026] Furthermore, the central clear area 11 does not have any configuration (e.g., a convex area or a concave area) intended to have the effect of inhibiting the progression of myopia or the effect of reducing hyperopia (hereinafter also referred to as the effect of inhibiting the progression of myopia, etc.).

[0027] The central clear area 11 of this embodiment (and the base area 13 and peripheral clear area 15 in the functional area 12, which will be described later) functions as a so-called single-focus lens. There are no particular limitations on the surface shape, but this embodiment illustrates a case in which the central clear area 11 has a spherical shape.

[0028] The functional region 12 is an annular region surrounding the central clear region 11 and includes a portion having a refractive power different from the wearer's prescribed refractive power. In this embodiment, the functional region 12 includes a plurality of defocus regions 14 (also referred to as convex regions) arranged in an island shape (i.e., spaced apart and not adjacent to each other) as portions having a refractive power different from the wearer's prescribed refractive power. In a plan view, the defocus regions 14 are arranged at equal intervals in the X direction and the Y direction, which intersects with the X direction at a predetermined angle. In other words, the arrangement of the defocus regions 14 in this embodiment is of the Cartesian coordinate system type described above. More specifically, the defocus regions 14 are independently and discretely arranged so that the centers of the defocus regions 14 form vertices of equilateral triangles, and the X direction and the Y direction intersect at 60 degrees. The remaining portion of the functional region 12 other than the defocus regions 14 constitutes a base region 13, which performs the same function as the central clear region 11. The functional region 12 is a region that, for example, causes a light beam incident from the object-side surface to exit from the eyeball-side surface, while preventing at least a portion of the light beam incident into the wearer's pupil from converging onto the retina, thereby enabling the eyeglass lens 10 of this embodiment to have an effect of inhibiting the progression of myopia.In addition, in this specification, unless otherwise specified, the term "planar view" refers to the state when viewed from the normal to the eyepoint of the outer surface (object-side surface or eyeball-side surface) of the eyeglass lens 10.

[0029] The multiple defocus regions 14 may be formed on at least one of the object-side surface or the eyeball-side surface of the eyeglass lens 10. In this embodiment, a case where multiple defocus regions 14 are provided only on the object-side surface of the eyeglass lens 10 is illustrated. The surface shape of the defocus regions 14 is preferably, for example, spherical. The number of multiple defocus regions 14 in the functional region 12 is not particularly limited, but is, for example, 20 to 500.

[0030] 5 is an enlarged schematic plan view of the vicinity of the eyepoint of the eyeglass lens 10 of this embodiment. As shown in FIG. 5 , a convex polygon 20 is assumed to be formed by connecting the centers of defocus regions 14 present at the boundary between the central clear region 11 and the functional region 12 in a planar view with imaginary lines. In this case, imaginary lines passing through the centers of two or more defocus regions 14 are defined as the sides of the convex polygon 20. The convex polygon 20 is configured so that the centers of the defocus regions 14 do not exist within the convex polygon 20 and the area of ​​the convex polygon 20 is maximized. Taking into account manufacturing errors of the defocus regions 14 and the like, the thickness of the imaginary line may be set to, for example, 0.1 mm, and if the centers of the defocus regions 14 exist on the sides of the convex polygon 20, the centers of the defocus regions 14 may not be considered to exist within the convex polygon 20.

[0031] The spectacle lens 10 of this embodiment is characterized in that the maximum value of the exterior angle of the convex polygon 20 is 36 degrees or less. This makes it possible to reduce the overlapping effect at the boundary between the central clear area 11 and the functional area 12, even if the arrangement of the defocus area 14 is of the Cartesian coordinate system type. Furthermore, it is preferable that the maximum value of the exterior angle of the convex polygon 20 is 30 degrees or less. This makes it possible to further reduce the overlapping effect at the boundary. Furthermore, from the viewpoint of not making the central clear area 11 too wide and not making the diameter of the defocus area 14 too small, and thus making it easier to obtain the effect of inhibiting the progression of myopia, it is preferable that the maximum value of the exterior angle of the convex polygon 20 is 27 degrees or more.

[0032] From the viewpoint of further reducing the overlapping effect at the boundary between the central clear region 11 and the functional region 12, the convex polygon 20 is preferably rotationally symmetric, preferably closer to a regular polygon, and preferably has an aspect ratio (horizontal:vertical) closer to 1:1. This is because the more the polygon deviates from a regular polygon, the more large the exterior angles that appear. Specifically, for example, it is preferable that the maximum exterior angle of the convex polygon 20 be 1.2 times or less the average exterior angle (360 / n degrees if the convex polygon 20 is an n-sided polygon). Furthermore, for example, it is preferable that the aspect ratio of the convex polygon 20 be in the range of 1:2 to 2:1.

[0033] The diameter of the defocus region 14 in a planar view is preferably, for example, 0.5 mm or more and 2.5 mm or less, and more preferably 0.8 mm or more and 1.4 mm or less. If the diameter of the defocus region 14 is less than 0.5 mm, it may be difficult to obtain the effect of inhibiting the progression of myopia. On the other hand, if the diameter of the defocus region 14 exceeds 2.5 mm, an object may be viewed through the defocus region 14, and the effect of inhibiting the progression of myopia may not be obtained properly. Note that in this embodiment, a case is described in which the diameter of the defocus region 14 within the functional region 12 is uniform. However, as long as the diameter of the defocus region 14 existing at least near the boundary between the central clear region 11 and the functional region 12 (e.g., a region within 10 mm of the boundary defined by the side of the convex polygon 20) is uniform, the diameter of the defocus region 14 may vary depending on the location in the functional region 12. When the diameter of the defocus region 14 varies depending on the location in the functional region 12 , the above-mentioned diameter of the defocus region 14 is that of the defocus region 14 that exists near the boundary between the central clear region 11 and the functional region 12 .

[0034] In this specification, the center (geometric center, center of gravity) of the convex polygon 20 is defined as the center of the central clear region 11. The distance r from the center of the convex polygon 20 to the center of the nearest defocus region 14 is defined as the radius of the central clear region 11. The distance r is preferably at least four times the distance p (hereinafter also referred to as the pitch p) between the centers of adjacent defocus regions 14. Under this condition, the outer angles of the convex polygon 20 can be easily reduced. Furthermore, from the viewpoint of preventing the central clear region 11 from being too wide and easily achieving the effect of inhibiting myopia progression, the distance r is preferably no more than five times the pitch p. Note that, in this embodiment, a case is described in which the pitch p of the defocus regions 14 within the functional region 12 is uniform. However, as long as the pitch p of the defocus regions 14 existing at least near the boundary between the central clear region 11 and the functional region 12 (e.g., the region within 10 mm of the boundary, with the side of the convex polygon 20 as the boundary) is uniform, the pitch p of the defocus regions 14 may vary depending on the location of the functional region 12. When the pitch p of the defocus area 14 varies depending on the location of the functional area 12 , the above-mentioned pitch p of the defocus area 14 refers to the defocus area 14 that exists near the boundary between the central clear area 11 and the functional area 12 .

[0035] The distance r is preferably 5.5 mm or more and 10 mm or less. Under these conditions, it is easy to make the outer angles of the convex polygon 20 small, and the central clear area 11 has an appropriate size, making it easier to obtain the effect of inhibiting the progression of myopia, etc.

[0036] The pitch p of the defocus region 14 is preferably 1.0 mm or more and 2.5 mm or less, and more preferably 1.2 mm or more and 2.0 mm or less. Under these conditions, it is easy to reduce the outer angle of the convex polygon 20, and the central clear region 11 has an appropriate size, making it easier to obtain the effect of inhibiting the progression of myopia, etc.

[0037] The difference (defocus power) between the refractive power of the defocus region 14 and the refractive power of the portion other than the defocus region 14 (for example, the base region 13) is preferably, for example, 0.5D or more and 10D or less.

[0038] The defocus regions 14 may be arranged in areas other than the functional region 12, but from the viewpoint of improving the wearing comfort of the eyeglass lens 10, it is preferable that, for example, 80% or more (more preferably 90% or more) of all the defocus regions 14 provided on the eyeglass lens 10 be arranged in the functional region 12.

[0039] In the functional region 12, the area ratio of the defocus region 14 is preferably, for example, 30% or more and 60% or less (more preferably 40% or more and 60% or less). If the area ratio of the defocus region 14 is less than 30%, there is a possibility that the myopia progression suppression effect, etc., may not be sufficiently obtained. In contrast, by setting the area ratio of the defocus region 14 to 30% or more, it is possible to sufficiently obtain the myopia progression suppression effect, etc. On the other hand, if the area ratio of the defocus region 14 exceeds 60%, there is a possibility that the wearing comfort and appearance of the eyeglass lens 10 may be adversely affected. In contrast, by setting the area ratio of the defocus region 14 to 60% or less, it is possible to maintain the wearing comfort and appearance of the eyeglass lens 10.

[0040] The peripheral clear area 15 is an annular area that realizes the wearer's prescribed refractive power and surrounds the functional area 12. In this embodiment, the peripheral clear area 15 performs the same function as the central clear area 11. Furthermore, because the peripheral clear area 15 is provided along the outer periphery of the spectacle lens 10 so as to surround the functional area 12, peripheral vision can be easily ensured.

[0041] By fitting the spectacle lens 10 of this embodiment into a predetermined frame, it is possible to realize eyeglasses including the spectacle lens 10 that have the effect of inhibiting the progression of myopia. The frame of the eyeglasses of this embodiment has, for example, a vertical width of 27 mm to 38 mm and a horizontal width (also referred to as lens width) of 42 mm to 50 mm. The above frame size is assumed to be a typical frame for children. From the perspective of efficiently achieving the effect of inhibiting the progression of myopia, the area of ​​the functional region 12 is preferably equal to or greater than half of the frame area. Furthermore, the area of ​​the central clear region 11 is preferably equal to or less than half of the frame area. To satisfy this condition, the diameter of the central clear region 11 needs to be equal to or less than 1 / √2 times (more preferably equal to or less than 1 / 2) the frame vertical width. Therefore, if the frame vertical width is 27 mm or more, the radius of the central clear region 11 (= the distance r from the center of the convex polygon 20 to the center of the nearest defocus region 14) is preferably equal to or less than 9.54 mm, more preferably equal to or less than 6.75 mm.

[0042] In eyeglasses having the eyeglass lens 10 of this embodiment, it is preferable to adjust the apparent central clear area 11 by moving the eyeglass lens 10 slightly away from the eye during fitting. If the central clear area 11 is slightly enlarged to reduce the overlapping image at the boundary between the central clear area 11 and the functional area 12, it is possible to adjust the apparent central clear area 11 by moving the eyeglass lens 10 slightly away from the eye during fitting. This is preferable because it reduces the risk of the eyeglass lens 10 hitting the eyelashes, etc.

[0043] Various commonly used lens substrates can be used as the lens substrate constituting the spectacle lens 10. The lens substrate may be, for example, a plastic lens substrate or a glass lens substrate. The glass lens substrate may be, for example, a lens substrate made of inorganic glass. As the lens substrate, a plastic lens substrate is preferred from the viewpoint of being lightweight and shatter-resistant. Examples of plastic lens substrates include styrene resins such as (meth)acrylic resins, polycarbonate resins, allyl resins, allyl carbonate resins such as diethylene glycol bisallyl carbonate resin (CR-39), vinyl resins, polyester resins, polyether resins, urethane resins obtained by reacting an isocyanate compound with a hydroxy compound such as diethylene glycol, thiourethane resins obtained by reacting an isocyanate compound with a polythiol compound, and cured products (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 may be undyed (colorless lenses) or dyed (dyed lenses). The thickness of the lens substrate is not particularly limited, but may be, for example, approximately 1 to 30 mm (center thickness). The refractive index of the lens substrate may be, for example, approximately 1.60 to 1.75. However, the refractive index of the lens substrate is not limited to this range, and may be within this range or may deviate above or below this range. In this specification, the refractive index refers to the refractive index for light with a wavelength of 500 nm.

[0044] (2) Modifications, etc. Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the present invention.

[0045] In the above-described embodiment, the case where the eyeglass lens 10 has the effect of inhibiting the progression of myopia has been described. However, for example, by changing the defocus area 14 (convex area) to a concave area, the present invention can also be applied to eyeglass lenses that have the effect of reducing hyperopia and eyeglasses having such eyeglass lenses.

[0046] Furthermore, for example, the present invention can be applied to similar spectacle lenses in general that provide a stimulus to the retina different from that provided by the naked eye or single-vision lenses by changing defocus and contrast characteristics. For example, the present invention can be applied to spectacle lenses that provide a stronger defocus stimulus to improve retinal blood flow and are expected to alleviate glaucoma, and to glasses that include such spectacle lenses.

[0047] Furthermore, for example, the present invention may be applied to clip-on type lenses attached to eyeglass frames. Clip-on type lenses have the problem of being prone to larger fitting errors compared to standard eyeglasses. In particular, when simply applied to conventional myopia progression inhibiting lenses, discomfort is likely to be felt due to the boundary position between the central clear area and the functional area differing from the original design position, or being different on the left and right. In other words, discomfort is caused by the presence of overlapping images in unexpected areas or different overlapping images on the left and right. In contrast, with the present invention, the overlapping image at the boundary between the central clear area and the functional area is inherently suppressed, so discomfort associated with the above problem is reduced.

[0048] Furthermore, the myopia progression control lenses (including clip-on lenses) of the present invention may be used for test wearing before prescribing myopia progression control lenses or for verifying the myopia progression control effects. Regarding a method for verifying the effectiveness of myopia progression control lenses, Lisa A. Ostrin et al., "IMI—The Dynamic Choroid: New Insights, Challenges, and Potential Significance for Human Myopia," suggests that short-term choroidal changes can provide clues for estimating the myopia control effects. Furthermore, one specific procedure based on this hypothesis is presented in "Short-term effect of simultaneous negative and positive defocus on axial length, and choroidal thickness in the human myopic eye" by Zeeshan Akhtar et al. Different lenses are worn in each eye, and the choroidal thickness and axial length are measured 60 minutes later, and changes over time relative to those measured before wearing are evaluated. The difference in the myopia control effects of the lenses worn in each eye can be inferred from the difference in changes over time between the left and right eyes. In the above-mentioned document, a comparison was made between a single-focus lens worn in the left eye and a myopia progression control lens worn in the right eye. If this experiment had been conducted using a conventional myopia progression control lens, the right eye would have experienced a blurred image caused by the boundary between the central clear area and the functional area, making the subject more likely to feel uncomfortable due to the imbalance between the left and right eyes. By replacing this with the myopia progression control lens of the present invention (e.g., a clip-on type) which has less blurred image itself, this discomfort can be suppressed. For the purpose of directly comparing multiple myopia progression control lenses, it is also possible to use the above method by wearing myopia progression control lenses with different designs for the left and right eyes (e.g., different sizes or shapes of the central clear area). In this case, too, when a conventional myopia progression control lens is used, discomfort would arise due to the imbalance in blurred image caused by the different boundary between the left and right eyes. However, by replacing this with the myopia progression control lens of the present invention, which has less blurred image itself, this discomfort can be suppressed.

[0049] Furthermore, when carrying out the above-mentioned test wearing or verification of the myopia progression suppression effect, instead of attaching a clip-on type lens to the eyeglass frame, this may be achieved by inserting a trial lens having the same configuration (central clear area and functional area) as the myopia progression suppression lens of the present invention into the trial frame. The trial frame also has the same problem as the clip-on type, in that the boundary position between the central clear area and the functional area is likely to vary greatly depending on the position of the insertion frame, but this problem is solved for the same reason.

[0050] Next, examples of the present invention will be described. These examples are merely examples of the present invention, and the present invention is not limited to these examples.

[0051] In this example, eyeglass lenses of Samples 1 to 5 were designed as eyeglass lenses that have the effect of inhibiting the progression of myopia. Fig. 6 is an enlarged planar schematic diagram of the vicinity of the eyepoint of the eyeglass lenses of Samples 1 to 5. Fig. 6 shows the convex polygon described in the above embodiment.

[0052] The spectacle lenses of Samples 1 to 5 have the following common configuration: Lens substrate: PC (polycarbonate) Refractive index of lens substrate: 1.589 Prescription refractive power (spherical refractive power): 0.00D Prescription refractive power (astigmatic refractive power): 0.00D Shape of defocus area: spherical (circular in plan view) Surface on which defocus area is formed: object-side surface Height of defocus area: 1 μm

[0053] In the eyeglass lenses of Samples 1 to 3, the arrangement of the defocus regions was a Cartesian coordinate system type in which the X direction and the Y direction intersect at 60 degrees, the pitch p of the defocus regions was 2 mm, and the diameter of the defocus regions was 1.4 mm. In the eyeglass lenses of Samples 4 and 5, the arrangement of the defocus regions was a Cartesian coordinate system type in which the X direction and the Y direction intersect at 90 degrees, the pitch of the defocus regions was 1.4 mm, and the diameter of the defocus regions was 1 mm.

[0054] Sample 1 was designed so that the distance r from the center of the convex polygon to the center of the nearest defocus area was three times the pitch p of the defocus areas (=6 mm), resulting in a maximum exterior angle of the convex polygon of 60 degrees.

[0055] Sample 2 was designed so that the distance r from the center of the convex polygon to the center of the nearest defocus area was 3.46 times (=6.92 mm) the pitch p of the defocus areas, resulting in a maximum exterior angle of the convex polygon of 60 degrees.

[0056] Sample 3 was designed so that the distance r from the center of the convex polygon to the center of the nearest defocus area was four times the pitch p of the defocus areas (=8 mm). As a result, the maximum value of the exterior angle of the convex polygon was 36 degrees.

[0057] Sample 4 was designed so that the distance r from the center of the convex polygon to the center of the nearest defocus area was 4.12 times (=5.77 mm) the pitch p of the defocus areas, resulting in a maximum exterior angle of the convex polygon of 26.6 degrees.

[0058] Sample 5 was designed so that the distance r from the center of the convex polygon to the center of the nearest defocus area was 5 times (=7 mm) the pitch p of the defocus areas, resulting in a maximum exterior angle of the convex polygon of 45 degrees.

[0059] Fig. 7 is a diagram showing the results of a simulation of how an original image similar to that shown in Fig. 2 appears blurred when the line of sight is shifted 2 mm along the side of the convex polygon from the defocus region indicated by the arrow in Fig. 6 for the spectacle lenses of Samples 1 to 5. A test was then conducted in which a large number of subjects were presented with the images shown in Fig. 7 and asked to compare how they perceived the images. As a result, the majority of subjects answered that they were less likely to experience overlapping images for Sample 3, in which the maximum outer angle of the convex polygon is 30 degrees, and Sample 4, in which the maximum outer angle of the convex polygon is 26.6 degrees.

[0060] From the above, it has been confirmed that by designing the convex polygon described in the above embodiment so that the maximum value of the exterior angle is 36 degrees or less, it is possible to realize eyeglass lenses that are less likely to cause overlapping images at the boundary between the central clear area and the functional area, even if the arrangement of the defocus area is of the Cartesian coordinate system type.

[0061] 10 eyeglass lens 11, 110 central clear area 12, 120 functional area 13, 130 base area 14, 140 defocus area 15 peripheral clear area 20, 200 convex polygon

Claims

1. A spectacle lens comprising: a central clear area that realizes the prescribed refractive power of a wearer and includes the eye point; and an annular functional area surrounding the central clear area, wherein the functional area has a base area that realizes the prescribed refractive power and a plurality of defocus areas having a refractive power different from the prescribed refractive power, wherein, in a planar view, the plurality of defocus areas are arranged side by side in the X direction and in the Y direction that intersects with the X direction at a predetermined angle, and wherein, when a convex polygon is formed on the boundary between the central clear area and the functional area in a planar view, with sides defined by imaginary lines passing through the centers of two or more of the defocus areas, the center of the defocus area does not exist within the convex polygon and when the area of ​​the convex polygon is maximized, the maximum value of the exterior angle of the convex polygon is 36 degrees or less.

2. The eyeglass lens according to claim 1, wherein the diameter of the defocus area is 0.5 mm or more and 2.5 mm or less.

3. The eyeglass lens according to claim 1, wherein the distance r from the center of the convex polygon to the center of the closest defocus area is at least four times the distance p between the centers of adjacent defocus areas.

4. The eyeglass lens according to claim 1, wherein the distance r from the center of the convex polygon to the center of the nearest defocus area is five times or less the distance p between the centers of adjacent defocus areas.

5. The eyeglass lens according to claim 1, wherein the distance r from the center of the convex polygon to the center of the closest defocus area is 5.5 mm or more and 10 mm or less.

6. A spectacle lens according to any one of claims 1 to 5, which has the effect of inhibiting the progression of myopia or reducing hyperopia.

Images