Patent Description:
One of factors that cause the progression of myopia is hyperopic blur (forming a clear image behind the retina) at the central part of the retina caused by an accommodation lag when viewing a near distance (insufficient or omission of lens accommodation with respect to lens accommodation power required for focusing on a near object). That is, a process is undergone in which a focal point of the central part of the retina is behind the retina, and an eye axis accordingly extends, and the eye becomes long in the front-rear direction, and as a result, myopia progresses. Therefore, provision of power for assisting accommodation power by eyeglasses when viewing a near distance to prevent a clear image from being formed behind the retina leads to suppression of the progression of myopia.

There is the idea that, to suppress the progression of myopia, not only an image forming state at the center of the retina but also an image forming state in the retina periphery are important. This theory is because the eye axis also extends at the retina periphery due to hyperopic blur and the retina periphery also causes the progression of myopia, and therefore, the progression of myopia can be suppressed by preventing a focal point on the retina periphery from being formed behind the retina by correction with eyeglasses.

Eyeglasses that prevent image formation behind the retina in the retina periphery as described above are disclosed in Patent Document <NUM>. Patent Document <NUM> discloses an eyeglass lens for suppressing the progression of myopia by forming a second refraction area of a plurality of convex lens-like island-shaped areas <NUM> independent from each other formed in a ring shape around a first ametropia correcting area <NUM> that corrects myopia as illustrated in, for example, <FIG>. With this eyeglass lens, a focal point on the retina periphery is corrected to be formed in front of the retina due to the plurality of island areas <NUM>, so that the progression of myopia can be suppressed.

Patent Document <NUM> discloses anti-myopia-progression spectacles of another type.

The eyeglass lens of Patent Document <NUM> is effective as an eyeglass lens for suppressing the progression of myopia, however, when a visual line is directed downward to view a near distance, the second refraction area (that is, island-shaped areas <NUM>) is in a ring shape, so that the visual line may overlap the second refraction area, and downward viewability may not be good. When viewing a near distance, an accommodation lag occurs theoretically, so that the myopia progression suppressing effect for a user who often views a near distance may deteriorate.

According to the present invention, the problems described above are improved and an eyeglass lens for suppressing the progression of myopia is provided which realizes good viewability through myopia refractive correction viewability and suppression of the progression of myopia at the same time.

In order to solve the problems above, an eyeglass lens according to claim <NUM> is provided. This eyeglass lens includes a first region for viewing a comparatively far distance, disposed at an upper side of a lens, and a second region disposed at a lower side than the first region and having more positive refractive power relatively than the first region, wherein a myopia progression suppressing region is disposed to surround a periphery of the first region and the second region.

With this eyeglass lens for suppressing the progression of myopia, a focal point on the retina periphery is disposed in front of the retina due to the myopia progression suppressing region surrounding the periphery of the first region and the second region, so that an effect of suppressing the progression of myopia is obtained. In addition, when viewing a near distance, the second region having more positive refractive power than the first region can be used, so that an accommodation lag is less likely to occur, and the effect of suppressing the progression of myopia is less likely to deteriorate.

The "first region for viewing a comparatively far distance, disposed at an upper side of a lens" and the "second region having more positive refractive power than the first region" is a lens having a lens power progressively added so as not to have a discontinuous portion between the first region and the second region namely a progressive power lens. Other examples not forming part of the claimed invention may be a lens having a discontinuous portion between the first region and the second region such as, for example, a BF (bifocal) lens accompanied by a small lens or a Franklin lens divided into two upper and lower portions.

Although a clear boundary may be provided between the first region, the second region and the myopia progression suppressing region in examples not forming part of the claimed invention, particularly in a lens having a progressively added lens power and having no discontinuous portion like a progressive power lens, depending on the shape of the myopia progression suppressing region, the region may have a portion overlapping a part (outer side) of the first region and the second region.

The myopia progression suppressing region is a region that prevents an image of incident light directed toward the retina periphery from being formed behind the retina by an optical effect, and is a region in which a landscape through the eyeglass lens cannot be clearly viewed. The myopia progression suppressing region is a region that transmits light but cannot form a focal point in the vicinity of the retina when a lens wearer views, such as, a group of several convex lenses according to the claimed invention, rough surface and other examples not falling within the scope of the claimed invention, described later.

According to the claimed invention, the myopia progression suppressing region consists of a group of a large number of convex lenses having a larger curvature than a front surface of the lens and spaced from each other so as to spread in two-dimensional directions.

In a case where the convex lens is a convex lens with a larger curvature than the lens front surface, when incident light is focused on the retina periphery, an image of the light is not formed behind the retina, so that an effect of suppressing the progression of myopia is obtained. In addition, when viewing a near distance, the second region having more positive refractive power than the first region can be used, so that an accommodation lag is less likely to occur, and the effect of suppressing the progression of myopia is less likely to deteriorate. In addition, in an eyeglass lens portion without a convex lens, the visual line is transmitted through, so that a clear vision region is accordingly widened.

The size of each convex lens preferably has a diameter of approximately <NUM> to <NUM>. All convex lenses may have or may not have the same size. A pupil diameter of a lens wearer is approximately <NUM>, and if the convex lenses become sufficiently larger than this pupil diameter, when the visual line passes through the convex lens portion, viewability depends on only the convex lenses, and the visual field is obstructed. The large number means not only a plurality but also a number necessary for obtaining the optical effect.

The group of convex lenses can suppress obstruction of the visual field in the myopia progression suppressing region to some degree by creating a state where light rays that do not pass through the convex lenses and light rays that pass through the convex lenses are mixed in a constant ratio in light rays passing through the pupil.

It is preferable that an interval between the convex lenses adjacent to each other is equal to the diameter of the convex lenses. Of course, the adjacent interval does not necessarily have to be equal to the diameter. The convex lenses do not necessarily have to all have the same shape, and may be arranged at even intervals or may be arranged randomly.

The convex lenses are preferably arranged so that a density of a portion overlapping the visual field (portion close to the lens center in the vertical direction), in particular, a near vision portion is lower (sparse) than a density of a portion far from the visual field.

For example, in a region having great aberration of a base lens and not assumed to be used for viewing an object through the region like a lateral side of a near vision portion of a progressive power lens, the convex lenses may be arranged at narrower intervals or at no intervals.

On the other hand, in a region having less aberration of the base lens and assumed to be used for viewing an object through the region like a lateral side of a far vision portion, the convex lenses are preferably arranged at sufficient intervals.

In the case of a progressive power lens, when eyeglasses slide down, the downward visual line does not pass through the near vision portion to which positive power is added, and the effect of suppressing an accommodation lag when viewing a near distance disappears. A lens wearer does not notice this since positive power is progressively added.

In order to prevent the problem above, at an upper side of the far vision portion, convex lenses are arranged at a high density by reducing or eliminating adjacent intervals, and accordingly, an effect of causing the wearer to notice the sliding down of the eyeglasses can also be obtained.

The myopia progression suppressing region consisting of a large number of convex lenses may be disposed as a ring-shaped region around the first region and the second region, or may be disposed at the left and the right so that major portions of the first region and second region at upper and lower sides from the center remain. When the myopia progression suppressing region is disposed at the left and the right, the myopia progression suppressing regions are preferably disposed in a region lower than the center. This disposition is preferable since the visual field in the region lower than the center is narrower than in the upper region although it is desirable to secure the visual field in a region higher than the center.

An eyeglass lens having these convex lenses is preferably manufactured by, for example, using a lens mold and curing a thermosetting monomer.

The group of the convex lenses disposed close to a center side of the lens has a smaller curvature than the group of the convex lenses disposed close to an outer circumference of the lens.

A portion close to the center side of the lens is likely to enter the visual field of a user, so that by setting a curvature to be relatively smaller than that of a portion close to the outer circumference of the lens, a sense of discomfort in use can be reduced.

According to the claimed invention, the group of a large number of the convex lenses consists of convex lenses having toroidal surface shapes, and are disposed at an angle that cancels out astigmatism of the lens.

The toroidal surface is a surface with different curvatures in perpendicular directions on a toric surface like a surface of a donut. Astigmatism is aberration caused by a difference between refractive powers in perpendicular directions on a lens surface, so that when a convex lens is a convex lens having a toroidal surface shape, by disposing a convex lens at an angle that cancels out astigmatism of the lens surface, the astigmatism is reduced.

In a further aspect not forming part of the claimed invention, the myopia progression suppressing region is a rough surface region in which the lens front surface scatters light, and is configured to surround the periphery of the first region and the second region.

Accordingly, an image of incident light directed toward the retina periphery is not formed behind the retina, so that the effect of suppressing the progression of myopia is obtained.

The rough surface region is a region in which light can be viewed although light is scattered and cannot be clearly viewed. The rough surface region may be formed of a surface enabling the entirety of the inside of the rough surface region to scatter light, and a large number of regions that scatter light may be arranged as a large number of spots spaced from each other so as to spread in two-dimensional directions in a planar view. For scattering light, for example, the rough surface region is preferably formed to have a large number of fine protrusions having a large number of surfaces different in angle as illustrated in <FIG>. According to this configuration, a frosted glass that scatters light is formed.

As the rough surface region, for example, a rough surface may be formed by directly applying sand blasting to the eyeglass lens, or an eyeglass lens having a rough surface region may be manufactured by using a lens mold after forming a rough surface on the lens mold by sand blasting.

In a further aspect not forming part of the claimed invention, the myopia progression suppressing region is configured so as to include a rough surface region that is formed into two or more independent island shapes.

Accordingly, when incident light is focused on the retina periphery, an image of the incident light is not formed behind the retina, so that an effect of suppressing the progression of myopia is obtained, and in addition, in an eyeglass lens portion having no island-shaped rough surface region, the visual line is transmitted and a clear vision region is accordingly widened.

Based on a front surface of the lens as a reference surface, the island-shaped rough surface region may be formed at the same height position as the reference surface as illustrated in <FIG>, may be formed at a position projecting upward as illustrated in <FIG>, or conversely, may be formed at a recessed position so as to form a recess as illustrated in <FIG>. A rough surface region may be composed of a number of independent island-shaped spots. In a further aspect, the myopia progression suppressing region is a region that surrounds the first region and the second region from the circumference so as to assume a ring-shaped donut form.

This represents a detailed example of a position where the myopia progression suppressing region is formed. As in this case, when the myopia progression suppressing region is a surrounding region assuming a ring-shaped donut form, it covers the entire region of the retina periphery, so that the effect of suppressing the progression of myopia increases.

According to a further aspect, the myopia progression suppressing region is disposed at left and right positions across the first region and the second region.

This represents a detailed example of a position where the myopia progression suppressing region is formed. As in this case, when the myopia progression suppressing region is provided at both sides of the first region and the second region, the visual field is secured from a distance field to a near field, and normal use as eyeglasses becomes less stressful. In a further aspect, a distribution density of the group of the convex lenses according to the claimed invention or the rough surface regions distributed in the myopia progression suppressing region is set to become lower at the lower side than at the upper side.

Accordingly, difficulty in viewing due to the presence of convex lenses in the visual line direction of a wearer when the wearer views downward is reduced. The distribution density may discontinuously or continuously and gradually change. In a further aspect, a distribution density of the group of the convex lenses according to the claimed invention or the rough surface region composed of a number of independent island-shaped spots disposed close to the center side of the lens is set to be lower than a distribution density at a position close to the outer circumference of the lens.

With this means, normal use as eyeglasses becomes less stressful.

According to a further aspect, the convex lenses disposed in the left-right direction of the second region produce smaller positive power than the convex lenses not disposed in the left-right direction of the second region.

Accordingly, when the wearer views downward, it can be prevented that power of the convex lenses overlap the power of the second region and causes excessive positive power.

According to a further aspect, a progressive zone region in which refractive power progressively changes is provided between the first region and the second region, and an addition gradient is set so that addition power is gradually added from the first region to the second region.

That is, the lens has a progressive power surface as a progressive power lens. When the eyeglass lens for suppressing the progression of myopia uses the first region and the second region as the progressive power lens described above, the visual line can be smoothly moved without image discontinuity (prism jump) on the boundary between the far vision portion and the near vision portion, and when viewing a near distance, the second region can be used and an accommodation lag is less likely to occur.

According to a further aspect, the myopia progression suppressing region is disposed at left and right positions across the progressive zone region and the second region.

That is, the myopia progression suppressing region is not disposed in the first region having a wide visual field, and since the visual field becomes comparatively narrow when viewing a near distance, by disposing the myopia progression suppressing region on both sides of the progressive zone region and the second region of the lower region, the progression of myopia can be suppressed while the visual field is secured.

For example, the myopia progression suppressing region is preferably a region surrounding the first region from a position <NUM> or more higher than a center of the first region. According to further aspect, the myopia progression suppressing region is formed on a surface on a side different from either the front surface or the back surface of the lens on which the first region, the second region, and the progressive zone region are provided.

Accordingly, the lens surface on the side where the convex lenses are formed can be formed into a base surface with a simple shape, so that the convex lenses can be easily designed, and a myopia progression suppressing region with a uniform shape is easily formed. The myopia progression suppressing region side is preferably formed as a surface on the object side.

According to a further aspect, with respect to a surface ratio obtained by dividing a total area occupied by the myopia progression suppressing region by a total area occupied by a portion other than the myopia progression suppressing region, the area ratio in the vicinity of the first region is smaller than the area ratio in the vicinity of the second region.

Accordingly, in a progressive power lens, the vicinity of the second region, in particular, left and right regions have a concentration of astigmatism and distortion, and frequency of viewing an object through these portions is low. However, these regions are regions that easily cause hyperopic blur in the retina periphery when viewing a near distance. Therefore, with this means, for example, bulges as the convex lens are disposed at a relatively higher density in these portions to efficiently exert the myopia progression suppressing effect without comparatively losing the visual field.

According to a further aspect, the myopia progression suppressing region consists of the group of the convex lenses, and refractive power of the convex lens disposed in the vicinity of the progressive zone region and the second region is set to be more positive than refractive power of the convex lens in the myopia progression suppressing region disposed in the vicinity of the first region.

It is assumed that as the refractive power of the convex lens body becomes more positive, the myopia progression suppressing effect increases, however, on the other hand, a refractive power difference from the portion other than the convex lenses increases, so that viewability through the myopia progression suppressing region deteriorates.

In addition, the regions across the second region have a concentration of astigmatism and distortion of the progressive power lens, so that the frequency of viewing an object through these portions is low. However, when viewing a near distance, these regions are regions that easily cause hyperopic blur in the retina periphery. Therefore, in the present means, by disposing convex lenses with more positive power in these regions, the myopia progression suppressing effect can be efficiently exerted without comparatively losing the visual field.

The aspects shown in the respective means described above can be combined according to the appended claims.

The disclosure of <CIT> including its specification, claims and drawings, can be referred to by the person of the art when considering the present disclosure.

By wearing an eyeglass lens for suppressing the progression of myopia according to the invention as claimed in this application, due to the myopia progression suppressing region surrounding the first region and the second region, a focal point on the retina periphery is disposed in front of the retina, so that an effect of suppressing the progression of myopia of a wearer is obtained. When viewing a near distance through this lens, the second region having more positive refractive power relatively than the first region can be used, so that an accommodation lag is less likely to occur, and the effect of suppressing the progression of myopia is less likely to deteriorate.

Hereinafter, detailed embodiments of an eyeglass lens for suppressing the progression of myopia (hereinafter, referred to as myopia suppressing lens) will be described.

As a first embodiment, a myopia suppressing lens <NUM> having progressive properties illustrated in <FIG> on a lens back surface was manufactured. In <FIG>, the X direction represents the horizontal direction during use of the eyeglass lens, and the Y direction represents the vertical direction in the same state. Basic design conditions for the myopia suppressing lens <NUM> are as follows.

For both of the left and right lenses, S -<NUM>. 00D, ADD <NUM>. 50D, inset theoretical value of <NUM>, and a progressive zone length of <NUM> were set. That is, as illustrated in <FIG>, the average power (lens power) is S -<NUM>. 00D in a far vision region, and the average power is <NUM>. 50D in a near vision region.

As seen from <FIG>, the far vision region higher than the center is a wide region and has no astigmatism, and this region narrows toward a lower side and becomes a narrow progressive zone region, and expands again in the near vision region. The region without astigmatism of the near vision region is narrower than the far vision region, but is wide enough when viewing a near distance. Astigmatism concentrates on left and right sides of the progressive zone region.

The myopia suppressing lens <NUM> is an aspheric lens made of a material with a refractive index of <NUM>, and has:.

As illustrated in <FIG> and <FIG>, on a lens front surface of the myopia suppressing lens <NUM>, myopia progression suppressing regions <NUM> are formed. The X direction in <FIG> is a horizontal direction during use of the eyeglass lens, and the Y direction is a vertical direction in the same state. The myopia progression suppressing region <NUM> consists of a group of a large number of dome-shaped small spots <NUM>. In the myopia progression suppressing region <NUM>, an area ratio of an area occupied by all spots <NUM> and an area occupied by a portion other than the spots <NUM> is set to <NUM> to <NUM> in the first embodiment.

The myopia progression suppressing regions <NUM> are disposed at both left and right positions avoiding a progressive zone at the center in a lens vertical direction in a lens lower region so as not to overlap a far vision region. These disposed positions are regions that approximately overlap with regions having a concentration of astigmatism in the astigmatism distribution chart in <FIG>. That is, the myopia progression suppressing regions <NUM> are disposed in regions that do not obstruct the visual field in the far vision region, the progressive zone region, and a near vision region, and are regions in which incident light is focused on the retina periphery.

As illustrated in <FIG>, the spots <NUM> in the first embodiment are dome-shaped convex lenses with a diameter of <NUM> molded integrally with the myopia suppressing lens <NUM>. The spot <NUM> has a perfect circular external shape as viewed from a vertex direction of the spot <NUM>. In the present first embodiment, the myopia progression suppressing regions <NUM> consist of groups of six curved rows separated into left and right and substantially along astigmatism directions convex inward respectively formed of pluralities of spots <NUM> arranged in series. In the row direction, the spots <NUM> are arranged at intervals of <NUM>, and the rows are successively arranged in an orderly manner so that a distance between row centerlines is <NUM>. The curve of the spots <NUM> is <NUM> curve based on <NUM>.

With the myopia suppressing lens <NUM> illustrated in the first embodiment, an effect of suppressing the progression of myopia of a wearer is obtained, and when viewing a near distance through this lens, the near vision region can be used, so that an accommodation lag is less likely to occur, and in this respect as well, the progression of myopia is suppressed. In addition, the myopia progression suppressing regions <NUM> are disposed in regions having a concentration of astigmatism, and do not obstruct normal vision.

A second embodiment is a variation of the first embodiment. A myopia suppressing lens <NUM> of the second embodiment has the same properties as the progressive properties illustrated in <FIG> of the myopia suppressing lens <NUM> of the first embodiment, and are designed under the same basic design conditions as those of the myopia suppressing lens <NUM>. In the myopia suppressing lens <NUM> of the second embodiment, a myopia progression suppressing region <NUM> is formed in a ring shape so as to surround a clear vision region <NUM> disposed at the lens center as illustrated in <FIG>. Spots <NUM> of the myopia suppressing lens <NUM> are individually shaped into the same convex lenses as the spots <NUM> of the first embodiment, but are arranged in a different pattern. The myopia progression suppressing region <NUM> consists of a group of <NUM> toric curved rows formed by concentrically arranging a large number of spots <NUM>. The large number of spots <NUM> are successively arranged at intervals of <NUM> to <NUM> in the row direction, and the rows are arranged in an orderly manner so that a distance between row centerlines is <NUM>.

With the myopia suppressing lens <NUM> of the second embodiment, it is assumed to obtain an effect of suppressing the progression of myopia by suppressing hyperopic blur in the retina periphery, and an effect of suppressing the progression of myopia by preventing an accommodation lag is further added.

In addition, in comparison with a progressive power lens to be frequently used as a means to simply prevent an accommodation lag and suppress the progression of myopia, by surrounding a lens use portion by spots, the effect can be prevented from being reduced by half due to a failure of alignment between a wearer, s eye position and the lens, such as sliding down of the eyeglasses.

It is also possible that a vertically long elliptic non-spot portion is provided so that the far vision portion and the near vision portion are formed as non-spot portions.

A third embodiment is also a variation of the first embodiment. A myopia suppressing lens <NUM> of the third embodiment has the same properties as the progressive properties illustrated in <FIG> of the myopia suppressing lens <NUM> of the first embodiment, and are designed under the same basic design conditions as those of the myopia suppressing lens <NUM>. As illustrated in <FIG>, myopia progression suppressing regions <NUM> of the third embodiment are disposed at both left and right sides avoiding, in particular, a region in which the visual line moves up and down (width of approximately <NUM> to <NUM>% of a lens diameter length in the left-right direction) at the center in a lens vertical direction. Spots <NUM> of the myopia suppressing lens <NUM> are individually shaped into the same convex lenses as the spots <NUM> of the first embodiment, but are arranged in a different pattern. The myopia progression suppressing regions <NUM> consist of groups disposed separately at the left and the right and each including <NUM> linear rows. The large number of spots <NUM> are arranged at intervals of <NUM> in the row direction, and the rows are successively arranged in an orderly manner so that a distance between row centerlines is <NUM>.

With the myopia suppressing lens <NUM> of the third embodiment, since the spots <NUM> are absent in the far vision region and the near vision region, while usability as an eyeglass lens is improved, an effect of suppressing the progression of myopia is extracted by surrounding the visual field by the myopia suppressing regions at the lateral portions. As compared with the first embodiment, spots are disposed at the lateral sides of the far vision portion as well, so that the effect of suppressing the progression of myopia caused by hyperopic blur in the retina periphery is considered to become relatively great.

A fourth embodiment is also a variation of the first embodiment. The myopia suppressing lens <NUM> of the fourth embodiment has the same properties as the progressive properties illustrated in <FIG> of the myopia suppressing lens <NUM> of the first embodiment, and are designed under the same basic design conditions as those of the myopia suppressing lens <NUM>.

In the fourth embodiment, spots <NUM> of myopia progression suppressing regions <NUM> disposed on a lens front surface have different shapes and different arrangement angles. In the fourth embodiment, description is given by focusing on the shapes and arrangement angles of the spots <NUM>. As illustrated in <FIG> and <FIG>, the large number of spots <NUM> of the fourth embodiment are formed of toroidal surfaces the lengths and curvatures of which become maximum and minimum in longitudinal and transverse directions orthogonal to each other. As illustrated in <FIG>, when C1 represents the curvature in the X direction and C2 represents the curvature in the Y direction, a sag amount Z (form of line passing through the center of the toroidal surface) of the spot <NUM> is defined as: <MAT>.

Here, it is assumed that, as illustrated in <FIG>, the myopia suppressing lens <NUM> that becomes a base has a local power of S -<NUM>. 25D C -<NUM>. 50D and an astigmatic axial direction (AX)<NUM> based on the X direction. On the other hand, the toroidal surface of the spot <NUM> is expressed as S +<NUM>. 25D and C +<NUM>. 50D in terms of diopter, and when the spot <NUM> overlaps the myopia suppressing lens <NUM> in a state where the phase is changed by <NUM>° rotation (AX100) based on the X direction, their C powers cancel each other and disappear. C power is astigmatism, and astigmatism at this position can be canceled out by disposing the spot <NUM> at a proper angle (phase). The proper angle is an angle that causes a maximum power direction of the local power of the myopia suppressing lens <NUM> and a maximum power direction of the toroidal surface of the spot <NUM> to become orthogonal to each other. However, a slight angle deviation is allowed, so that by roughly disposing the spots in such angle directions, astigmatism in the myopia progression suppressing region <NUM> can be canceled, and the burden on the wearer's eye can be reduced.

As illustrated in <FIG>, as a result of providing progressive properties to the spots <NUM>, in the peripheral region of the myopia suppressing lens <NUM> in which astigmatism occurs, the spots <NUM> are disposed to cancel the astigmatism. The maximum power direction of the toroidal surface of the spot <NUM> disposed on a contour line of astigmatism is substantially orthogonal to the astigmatism. A phase of the spot <NUM> not on the contour line is also determined in consideration of astigmatism. A larger number of spots (also in various sizes) than in <FIG> can be disposed according to the direction of astigmatism.

Accordingly, when an image of a light ray passing through the spot region is formed before the retina, the focal depth of the light ray is prevented from being extended according to astigmatism of the base lens, and the image can be stably formed before the retina.

A fifth embodiment is a variation of the second embodiment. As illustrated in <FIG>, in a myopia suppressing lens <NUM> of the fifth embodiment, the shape of a myopia progression suppressing region <NUM> is formed around a clear vision region <NUM> as with the ring-shaped myopia progression suppressing region <NUM> of the second embodiment. In the fifth embodiment, unlike the second embodiment, spots <NUM> constituting the myopia progression suppressing region <NUM> are disposed to become sparser, that is, lower in density toward the lower side.

With this myopia suppressing lens <NUM>, viewing through, in particular, the near vision region is easier.

In the first to fifth embodiments, the curves of the convex lens shapes of the spots <NUM>, <NUM>, <NUM>, and <NUM> are formed with the same curvature, and accordingly, positive powers added by the spots <NUM>, <NUM>, <NUM>, and <NUM> are also the same in the myopia progression suppressing regions <NUM>, <NUM>, <NUM>, and <NUM>.

However, in any of these lenses, the lens power (S power) of the near vision region is positive, so that when the positive powers of the spots <NUM>, <NUM>, <NUM>, and <NUM> are added, a portion overlapping a region to which power is added in the near vision region provides excessive correction. Therefore, it is preferable that positive powers of the spots <NUM>, <NUM>, <NUM>, and <NUM> disposed in and lower than the near vision region are made smaller (smaller in curvature) than positive powers of the higher spots <NUM>, <NUM>, <NUM>, and <NUM>.

For example, when it is assumed that power of +3D is relatively added to the myopia suppressing region,.

A seventh embodiment is a variation of the second embodiment. In a myopia suppressing lens <NUM> of the seventh embodiment, as in the second embodiment, the myopia progression suppressing region <NUM> consisting of the spots <NUM> is disposed in a ring shape so as to surround the clear vision region <NUM> disposed at a lens center. However, in the seventh embodiment, as illustrated in <FIG>, the spots <NUM> disposed close to the center side of the lens are disposed at a lower distribution density than the spots <NUM> disposed close to the outer circumference of the lens.

With this myopia suppressing lens <NUM>, the visual line frequently passes through the clear vision region <NUM>, so that normal use as eyeglasses becomes less stressful.

An eighth embodiment is a variation of the third embodiment. A distribution state of the spots <NUM> in two-dimensional directions in the myopia progression suppressing regions <NUM> in a planar view is the same as in the third embodiment. That is, as in the third embodiment, the myopia progression suppressing regions <NUM> are disposed at both left and right positions avoiding in particular a region in which the visual line moves up and down (width of approximately <NUM> to <NUM>% of a lens diameter length in the left-right direction) at the center in a lens vertical direction. However, in the eighth embodiment, refractive power of the spots <NUM> in a progressive zone region and a near vision region lower than the C line in <FIG> is designed to be more positive than refractive power of the spots <NUM> in the far vision region higher than the C line. In this eighth embodiment, the refractive power is more positive by <NUM>.

In this way, by disposing convex lenses having more positive power at portions where astigmatism and distortion of the progressive power lens concentrate and the visual line rarely passes through, an effect of suppressing the progression of myopia can be efficiently exerted without comparatively losing the visual field.

A ninth embodiment is a variation of the eighth embodiment.

In the eighth embodiment, the spots <NUM> disposed around the far vision region and the spots <NUM> disposed around the near vision region (lower than C line) are made different in refractive power from each other, however, instead of changing the refractive power from a certain line as in the eighth embodiment, the area ratio of the spots may be gradually changed. The ninth embodiment is an embodiment in which a distribution density (area ratio) of spots in the myopia progression suppressing region is changed.

As illustrated in <FIG>, it is possible that in a region higher than the vicinity of the C line, an area ratio of the spots <NUM> and a portion other than the spots <NUM> is set to "sparse" (for example, approximately <NUM> to <NUM>), and in a region lower than the vicinity of the C line, the area ratio of the spots <NUM> and the portion other than the spots <NUM> is set to "dense" relative to the region higher than the C line (for example, approximately <NUM> to <NUM>).

A tenth example is an example in which a large number of spots in a myopia progression suppressing region are not convex lenses but rough surfaces. In the tenth embodiment, as illustrated in <FIG>, opaque glass-like island-shaped spots <NUM> are formed on a transparent lens base material in a planar view. In the tenth embodiment, a myopia suppressing lens in which the spots <NUM> are disposed at the same positions as, for example, distributed positions of the spots <NUM>, <NUM>, <NUM>, and <NUM> in planar views in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG> can be formed. A myopia suppressing lens <NUM> having a myopia progression suppressing region including a large number of spots <NUM> successively disposed at intervals in two-dimensional directions can bring about the same effect as that of the myopia suppressing lenses of the first to ninth embodiments described above.

The above embodiments are merely described as detailed embodiments for illustrating the principle and concept of the present invention. That is, the present invention is not limited to the embodiments described above. The present invention can also be embodied by, for example, the following modifications.

The invention as claimed in this application is not limited to the configurations described in the above embodiments. Components of the respective embodiments and modifications may be selected and combined according to the appended claims.

Claim 1:
An eyeglass lens for suppressing the progression of myopia, comprising: a first region for viewing a comparatively far distance, disposed at an upper side of a lens (<NUM>); and a second region disposed at a lower side than the first region and having more positive refractive power relatively than the first region, wherein
a myopia progression suppressing region (<NUM>) is disposed to surround a periphery of the first region and the second region,
wherein the myopia progression suppressing region (<NUM>) consists of a group of several convex lenses (<NUM>) having a larger curvature than a front surface of the lens (<NUM>) and spaced from each other so as to spread in two-dimensional directions,
characterized in that the eyeglass lens is a progressive power lens, and
in that the group of several convex lenses consists of convex lenses having toroidal surface shapes (<NUM>), and are disposed at an angle that cancels out astigmatism of the lens (<NUM>).