TECHNICAL FIELD

The present invention relates to an ophthalmic lens, a method for designing the same, a method for manufacturing the same, and an ophthalmic lens set.

DESCRIPTION OF RELATED ART

As an ophthalmic lens, for example, a contact lens, an intraocular lens, etc., are known (in this specification, a spectacle lens is excluded as an ophthalmic lens). For example, a multifocal contact lens (multifocal lens) can be given as a contact lens, which ensures near dioptric power for viewing near distance and distance dioptric power for viewing far distance, with a single lens. The configuration of this multifocal lens includes, for example, a configuration in which a near portion with a near dioptric power is centrally disposed in a lens, and a distance portion with a distance dioptric power is annularly disposed at the outer edge of the near portion in the lens (For example, [FIG. 1] [FIG. 2] of patent document 1). On the contrary, a configuration is also known in which a distance portion with distance dioptric power is centrally disposed in the lens, and a near portion with near dioptric power is annularly disposed at the outer edge of the distance portion (For example, [FIG. 12] of patent document 2).

PRIOR ART DOCUMENT

Patent Document

[Patent Document 1] Japanese Published Patent Application No. 2006-505011

[Patent Document 2] WO 2006/129707

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

Before describing the subject of the present invention, an optical portion will be described. An example of the multifocal lens is as follows: a near portion with near dioptric power is centrally disposed in the lens, and a distance portion with distance dioptric power is annularly disposed at the outer edge of the near portion (multifocal lens, also simply called a lens).

First,FIG. 1is a schematic plan view of a conventional multifocal lens (top view when looking at a direction of the earth from a direction of the heavens in a direction of an optical axis, when the lens is placed on a horizontal base with a front surface (convex surface) of the lens facing up. The same applies to a planar view). A distance on the lens in planar view is referred to as a planar view distance. Reference numerals1denotes a near portion,2denotes a distance portion,3denotes an optical portion,4denotes a peripheral portion, and5denotes a multifocal contact lens. The reference numerals will be omitted hereinafter.

As shown inFIG. 1, a near portion is centrally disposed, and an annular distance portion is disposed at the outer edge of the near portion, with an optical center O of the lens being concentric. In this example, the optical center O is made to coincide with a geometric center. Thus, the optical portion having the near portion and the distance portion is configured. Further, there is an annular peripheral portion at the further outer edge of the optical portion. The peripheral portion usually has a flange shape that can easily enter the back of an eyelid when the lens is placed on a cornea. Namely, the optical portion and the peripheral portion constitute the lens of this example. However, the optical portion and the peripheral portion are each distinguished to perform the above-mentioned function, and there is not a clear visible boundary such as a step between the optical portion and the peripheral portion.

Initially, when plotting the power as viewed from the end F to the end F′ in the X-X′ direction (that is, a radial direction), the near dioptric power should be ensured in the near portion (N-N′ region), and the distance dioptric power should be ensured in the distance region (F-N region and N′-F′ region).

However, an actual lens does not necessarily have such a power plot. This is shown inFIG. 2.FIG. 2is a diagram of plotting the power when the optical portion of a conventional multifocal contact lens is viewed from the end F to the end F′ in the X-X′ direction. The horizontal axis indicates a distance from the optical center O at X-X′ when the lens is viewed in plan. The vertical axis indicates a lens power (unit: diopter [D]), in which the power is increased toward the upper side, and the power is decreased toward the lower side. The term “power” as used herein refers to the power provided by a difference in the shape (curvature) of both surfaces of the lens.

As shown inFIG. 2, in the case of an actual lens, when the power change is viewed in a direction from the optical center O toward the periphery (X direction; hereinafter, this direction is used unless otherwise specified), the power is decreased gradually at the beginning, then the power is decreased sharply, and decrease of the power becomes gradual again, and finally reaches a distance dioptric power.

In an example of the multifocal contact lens (multifocal lens) mentioned here, it is necessary to provide a portion where the power changes. In view of this situation, the decrease of the power when viewed in the X direction cannot but be a state as shown inFIG. 2(or [FIG. 1] [FIG. 2] of Patent Document 1). Therefore, in the conventional lens, there is also a case where a power changing portion is positioned as a transition portion or an intermediate portion (Reference numeral 104 in FIG. 12 of Patent Document 2). In such a case, it is impossible to ensure the near dioptric power in the hatched portion ofFIG. 2(that is, the portion where the power starts to be decreased). Namely, the following situation sometimes occurs: in the portion that requires a near vision, sufficient near dioptric power cannot be ensured.

In order to prevent such a situation, as shown inFIG. 3, a position at which the power is decreased when viewed in the X direction and the X′ direction, is moved away from the optical center O, as compared withFIG. 2. In this way, the near dioptric power can be ensured in the near portion (region of N-N′) which is set in advance.

However, when the above method is adopted, as shown inFIG. 3, the distance portion disposed at the outer edge of the near portion is narrowed this time. Further, as a result, it is not possible to ensure the near dioptric power in the hatched portion inFIG. 3(that is, the portion where the power starts to be decreased).

In the optical portion of the multifocal contact lens, it is very important to dispose the distance portion and the near portion in a balanced manner with respect to a pupil. Therefore, it is important to keep a good balance between the distance portion and near portion, not only in the multi focal contact lens, but also in an ophthalmic lens including other contact lens or intraocular lens.

An object of the present invention is to keep a good balance between the near portion and the distance portion disposed at the outer edge of the near portion while ensuring the near dioptric power sufficiently in the near portion when the near portion is centrally disposed in the optical portion, and to keep a good balance between the distance portion and the near portion disposed at the outer edge of the distance portion while ensuring the distance dioptric power sufficiently in the distance portion when the distance portion is centrally disposed in the optical portion.

Means for Solving the Problem

In order to solve the above-described problem, and after a diligent study by the present inventors, it is found that the key to solving this problem is to eliminate the hatched portion inFIG. 2. The reason for generating the hatched portion inFIG. 2is that the decrease of the power must already be started in the near portion when viewed in the X direction. Therefore, the present inventors obtain a technique of obtaining the near dioptric power at the end N of the near portion even if the decrease of the power starts in the near portion, by increasing the power more than the near dioptric power before start of the decrease of the power in the near portion as shown inFIG. 4(b). When the near portion is centrally disposed in this example, the near dioptric power is intensified (in a direction in which the nearer view can be seen, ie, in a positive direction, for example, 5.00D→5.10D), and thereafter the power may be decreased to the distance dioptric power, and conversely, when the distance portion is centrally disposed, the distance dioptric power is intensified (in a direction in which the far view can be seen, ie, in a negative direction, for example, 0.00D-0.10D), and then the power may be increased to the near dioptric power.

As a result of obtaining the above findings, the present inventors adopt a configuration of the present invention described below. The preferred embodiments described below can be combined as appropriate.

According to a first aspect of the present invention, there is provided an ophthalmic lens, including:

an optical portion having:

a near portion with a near dioptric power for viewing near distance; and

a distance portion with a distance dioptric for viewing a distance further than the near distance;

with the near portion or the distance portion being centrally disposed,

wherein a portion that is not centrally disposed is annularly disposed at an outer edge of the near portion or the distance portion,

the near portion or the distance portion centrally disposed in the optical portion having a portion A in which power is intensified and then weakened when viewed in X direction from a center to a periphery, and having a portion A′ in which power is intensified and then weakened when viewed in X′ direction from the center to the periphery, which is an opposite direction to the X direction.

According to a second aspect of the present invention, there is provided the ophthalmic lens of the first aspect,

wherein the near portion is centrally disposed in the optical portion, and in the portion A and the portion A′, the power is intensified to nearer than the near dioptric power and then weakened to a distance dioptric power.

According to a third aspect of the present invention, there is provided the ophthalmic lens of the second aspect, wherein there is only one point where the power is locally maximum in the portion A, and there is only one point where the power is locally maximum in the portion A′.

According to a fourth aspect of the present invention, there is provided the ophthalmic lens of the second or third aspect, wherein a planar view distance between the portion where the power is locally maximum in the portion A and the portion where the power is locally maximum in the portion A′ is 1.0 to 2.8 mm.

According to a fifth aspect of the present invention, there is provided the ophthalmic lens of any one of the second to fourth aspects, wherein a difference between a local maximum value of the power and the near dioptric power in the portion A is 0.05 to 0.25 D, and a difference between a local maximum value of the power and the near dioptric power in the portion A′ is also 0.05 to 0.25D.

According to a sixth aspect of the present invention, there is provided the ophthalmic lens of the first aspect, wherein the distance portion is centrally disposed in the optical portion, and in the portion A and the portion A′, the power is intensified to farther than the distance dioptric power and then weakened to a near dioptric power.

According to a seventh aspect of the present invention, there is provided the ophthalmic lens of the sixth aspect, wherein there is only one point where the power is locally minimum in the portion A, and there is only one point where the power is locally minimum in the portion A′.

According to an eighth aspect of the present invention, there is provided the ophthalmic lens of the sixth or the seventh aspect, wherein a planar view distance between the point where the power is locally minimum in the portion A and the point where the power is locally minimum in the portion A′ is 1.0 to 2.8 mm.

According to a ninth aspect of the present invention, there is provided the ophthalmic lens of any one of the sixth to eighth aspects, wherein a difference between a local minimum value of the power and the distance dioptric power in the portion A is 0.05 to 0.25 D, and a difference between a local minimum value of the power and the distance dioptric power in the portion A′ is also 0.05 to 0.25D.

According to a tenth aspect of the present invention, there is provided the ophthalmic lens of any one of the first to ninth aspects, wherein the ophthalmic lens is a contact lens (a soft contact lens or a hard contact lens, preferably the soft contact lens).

According to an eleventh aspect of the present invention, there is provided the ophthalmic lens of any one of the first to ninth aspects, wherein the ophthalmic lens is an intraocular lens.

According to a twelfth aspect of the present invention, there is provided a method for designing an ophthalmic lens including:

an optical portion having:

a near portion with a near dioptric power for viewing near distance;

and

a distance portion with a distance dioptric for viewing a distance further than the near distance;

with the near portion or the distance portion being centrally disposed,

wherein a portion that is not centrally disposed is annularly disposed at an outer edge of the near portion or the distance portion,

and the near portion or the distance portion centrally disposed in the optical portion has a portion A in which power is intensified and then weakened when viewed in X direction from a center to a periphery, and has a portion A′ in which power is intensified and then weakened when viewed in X′ direction from the center to the periphery, which is an opposite direction to the X direction.

According to a thirteenth aspect of the present invention, there is provided the method of the twelfth aspect, wherein an ophthalmic lens is designed so that the near portion is centrally disposed in the optical portion, and in the portion A and the portion A′, the power is intensified to nearer than the near dioptric power and then weakened to a distance dioptric power.

According to a fourteenth aspect of the present invention, there is provided the method of the thirteenth aspect, wherein there is only one point where the power is locally maximum in the portion A, and there is only one point where the power is locally maximum in the portion A′.

According to a fifteenth aspect of the present invention, there is provided the method of the thirteenth or the fourteenth aspect, wherein a planar view distance between the portion where the power is locally maximum in the portion A and the portion where the power is locally maximum in the portion A′ is 1.0 to 2.8 mm.

According to a sixteenth aspect of the present invention, there is provided the method of any one of the thirteenth to fifteenth aspects, wherein a difference between a local maximum value of the power and the near dioptric power in the portion A is 0.05 to 0.25 D, and a difference between a local minimum value of the power and the near dioptric power in the portion A′ is also 0.05 to 0.25D.

According to a seventeenth aspect of the present invention, there is provided the method of the twelfth aspect, wherein the distance portion is centrally disposed in the optical portion, and in the portion A and the portion A′, the power is intensified farther than the distance dioptric power and then weakened to a near dioptric power.

According to an eighteenth aspect of the present invention, there is provided the method of the seventeenth aspect, wherein there is only one point where the power is locally minimum in the portion A, and there is only one point where the power is locally minimum in the portion A′.

According to a nineteenth aspect of the present invention, there is provided the method of the seventeenth or the eighteenth aspect, wherein a planar view distance between the portion where the power is locally minimum in the portion A and the portion where the power is locally minimum in the portion A′ is 1.0 to 2.8 mm.

According to a twentieth aspect of the present invention, there is provided the method of any one of the seventeenth to nineteenth aspect, wherein a difference between a local minimum value of the power and the distance dioptric power in the portion A is 0.05 to 0.25 D, and a difference between a local minimum value of the power and the distance dioptric power in the portion A′ is also 0.05 to 0.25D.

According to a twenty-first aspect of the present invention, there is provided the method of any one of the twelfth to twentieth aspects, wherein the ophthalmic lens is a contact lens (a soft contact lens or a hard contact lens, preferably the soft contact lens).

According to a twenty-second aspect of the present invention, there is provided the method of any one of the twelfth to twentieth aspect, wherein the ophthalmic lens is an intraocular lens.

According to a twenty-third aspect of the present invention, there is provided a method for manufacturing an ophthalmic lens, including

designing an ophthalmic lens by the method for designing an ophthalmic lens according to any of the twelfth to twenty-second aspect; and

manufacturing a designed ophthalmic lens by a processing device.

Further, an aspect of an ophthalmic lens set including a plurality of the above ophthalmic lenses is as follows. The above-described preferable aspects may be suitably combined to examples given as aspects of the present invention, etc., in this specification, can be suitably combined and can be included in the embodiment of the present application.

According to a twenty-fourth aspect of the present invention, there is provided an ophthalmic lens set including a plurality of ophthalmic lenses each including:

an optical portion having:

a near portion with a near dioptric power for viewing near distance; and

a distance portion with a distance dioptric for viewing a distance farther than the near distance;

with the near portion or the distance portion being centrally disposed,

wherein a portion that is not centrally disposed is annularly disposed at an outer edge of the near portion or the distance portion, and

the near portion or the distance portion centrally disposed in the optical portion has a portion A in which power is intensified and then weakened when viewed in X direction from a center to a periphery, and having a portion A′ in which power is intensified and then weakened when viewed in X′ direction from the center to the periphery, which is an opposite direction to the X direction.

Further, the other aspects that can be combined with the above aspects are as follows.

According to a twenty-fifth aspect of the present invention, there is provided the ophthalmic lens set of each aspect,

wherein the near portion is centrally disposed in the optical portion, and

the portion A and the A′ are the portions in which power is increased and then decreased (preferably the power continues to be decreased) to a near dioptric power or less, and then the power is decreased (preferably the power continues to be decreased) up to a distance dioptric power in the near portion.

According to a twenty-sixth aspect of the present invention, there is provided the ophthalmic lens set of the twenty-fifth aspect, wherein preferably there are two convex portions (ie, one concave portion) on an upper side when viewed in a power plot.

According to a twenty-seventh aspect of the present invention, there is provided the ophthalmic lens set of the twenty-fifth or twenty-sixth aspect, wherein the planar view distance is preferably 1.0 to 2.8 mm, a lower limit is more preferably 1.2 mm, still more preferably 1.4 mm, and very preferably 1.6 mm, and an upper limit is more preferably 2.6 mm, still more preferably 2.4 mm.

According to a twenty-eighth aspect of the present invention, there is provided the ophthalmic lens set of any one of the twenty-fifth to twenty-seventh aspect, wherein preferably a difference between a local maximum value of the power and a near dioptric power in portion A is 0.05 to 0.25 D, and a difference between a local maximum value of the power and a near dioptric power in portion A′ is also 0.05 to 0.25 D. A lower limit of each is more preferably 0.10 D, further preferably 0.12 D, very preferably 0.15 D, and upper limit is more preferably 0.20D.

According to a twenty-seventh aspect of the present invention, there is provided the ophthalmic lens set of any one of the twenty-fifth to twenty-eighth aspect, wherein when a straight line X-X′ is rotated from 0 to 180° around the optical center O with respect to a lens, a portion having a shape in which the power in the portion A and the portion A′ is intensified to nearer than the near dioptric power and then weakened to the distance dioptric power, is preferably 50 area % or more, more preferably 80 area % or more, and further preferably 90 area % or more of an optical portion.

According to a thirtieth aspect of the present invention, there is provided the ophthalmic lens set of each aspect, wherein

the distance portion is centrally disposed in the optical portion, and

the portion A and the A′ are the portions in which power is decreased and then increased (preferably the power continues to be increased) to the distance dioptric power or more, and then the power is increased (preferably the power continues to be increased) up to the near dioptric power, in the distance portion.

According to a thirty-first aspect of the present invention, there is provided the ophthalmic lens set of the thirtieth aspect, wherein preferably there are two concave portions (i.e., one convex portion on an upper side) when viewed in a power plot.

According to a thirty-second aspect of the present invention, there is provided the ophthalmic lens set of the thirtieth or thirty-first aspect, wherein the planar view distance is preferably 1.0 to 2.8 mm, a lower limit is more preferably 1.2 mm, still more preferably 1.4 mm, and very preferably 1.6 mm, and an upper limit is more preferably 2.6 mm, still more preferably 2.4 mm.

According to a thirty-third aspect of the present invention, there is provided the ophthalmic lens set of any one of the thirtieth to thirty-second aspects, wherein preferably a difference between a local minimum value of the power and the distance dioptric power in the portion A is 0.05 to 0.25 D, and a difference between a local minimum value of the power and the distance dioptric power in the portion A′ is also 0.05 to 0.25 D. A lower limit of each is more preferably 0.10 D, further preferably 0.12 D, very preferably 0.15 D and an upper limit is more preferably 0.20 D.

According to a thirty-fourth aspect of the present invention, there is provided the ophthalmic lens set of any one of the thirtieth to thirty-third aspects, wherein when a straight line X-X′ is rotated from 0 to 180° around the optical center O with respect to a lens, a portion having a shape in which the power in the portion A and the portion A′ is intensified to farther than the distance dioptric power and then weakened to the near dioptric power, is preferably 50 area % or more, more preferably 80 area % or more, and further preferably 90 area % or more of the optical portion.

According to a thirty-fifth aspect of the present invention, there is provided the ophthalmic lens set of each aspect, wherein

the ophthalmic lens is an intraocular lens, and

the ophthalmic lens includes a lens body having the optical portion, and support portions extending from the lens body.

The support portions are, for example, two support portions extending in an arm shape from the lens body.

According to a thirty-sixth aspect of the present invention, there is provided an ophthalmic lens, a method for designing the same, and a method for manufacturing the same, the ophthalmic lens including a plurality of ophthalmic lenses each including:

an optical portion having:

a near portion with a near dioptric power for viewing near distance; and

a distance portion with a distance dioptric for viewing a distance farther than the near distance;

with the near portion or the distance portion being centrally disposed,

wherein a portion that is not centrally disposed is annularly disposed at an outer edge of the near portion or the distance portion, and

the near portion or the distance portion centrally disposed in the optical portion has a portion A in which power is intensified and then weakened when viewed in X direction from a center to a periphery, and there is an inflection point of the power when viewed in X′ direction from the center to the periphery, which is an opposite direction to the X direction.

Advantage of the Invention

According to the present invention, a good balance can be kept between the near portion and the distance portion disposed at the outer edge of the near portion while ensuring the near dioptric power sufficiently in the near portion when the near portion is centrally disposed in the optical portion, and a good balance can be kept between the distance portion and the near portion disposed at the outer edge of the distance portion while ensuring the distance dioptric power sufficiently in the distance portion when the distance portion is centrally disposed in the optical portion.

