WO2006134649A1

WO2006134649A1 - Contact lens of various materials

Info

Publication number: WO2006134649A1
Application number: PCT/JP2005/010965
Authority: WO
Inventors: Yuji Goto; Ryo Matsushita; Yukihisa Sakai; Tadashi Sawano
Original assignee: Menicon Co., Ltd.
Priority date: 2005-06-15
Filing date: 2005-06-15
Publication date: 2006-12-21
Also published as: JP4608544B2; JPWO2006134649A1

Abstract

A contact lens of various materials having a novel structure and realizing excellent wearing feeling by reducing strange feeling when it is applied to an eye. Boundary (60) between the central portion (56) formed of a hard lens material and the outer circumferential portion (58) formed of a soft lens material is arranged such that the separation distance between the rear surface side end of the boundary (60) on the rear surface of a leans and the surface (12) of an eyeball is set to be larger than that between the rear surface at an optical portion (16) and the surface (12) of an eyeball or that between the rear surface at the circumferential portion (18) and the eyeball surface, whichever is shorter, thus preventing the rear surface side end (62) of the boundary (60) from touching the surface (12) of eyeball.

Description

Multi-material contact lens technology

TECHNICAL FIELD [0001] The present invention relates to a contact lens that is superimposed on the surface of an eyeball and has an assisting or correcting action on the optical characteristics of the eye, and in particular, a multi-material contact lens formed of a plurality of parts made of different materials. It is about.

Background art

[0002] Conventionally, contact lenses have been provided that are attached to the surface of the cornea for the purpose of correcting myopia, hyperopia, astigmatism, presbyopia, and the like. The performance required for a powerful contact lens includes (a) in addition to stable display of the desired optical characteristics, and contact with a sensitive cornea or eyelid. Therefore, it is important that (i) the feeling of foreign matter during wearing is sufficiently suppressed and (ii) oxygen supply to the corneal surface is sufficiently performed by wearing tears when worn.

[0003] Incidentally, contact lenses are generally classified into a hard type contact lens formed of a hard material and a soft type contact lens formed of a soft material. In general, hard contact lenses have excellent shape stability and optical characteristics, but they also have a great sense of foreign matter when worn with a large amount of movement on the eyeball. On the other hand, the soft type is superior in wearing feeling because it has a small amount of movement on the eyeball, but because it is made of a soft material, it has optical properties that are easily deformed and does not reach the node type contact lens. There wasn't.

[0004] Therefore, an attempt has been made to develop a contact lens having the advantages of such a hard-type contact lens and a soft-type contact lens. — As shown in 120655), a composite contact lens as a kind of multi-material contact lens in which the edge of a flexible material is joined to the entire outer periphery of a lens core (optical part) that also has a hard material force Has been proposed. In such a composite contact lens, by forming the lens core as an optical part from a hard material, it is possible to suppress the shape change in the optical part and realize excellent optical characteristics, and also from a soft material. It was expected that the feeling of foreign matter during wearing could be reduced by providing the formed edge on the entire outer periphery of the lens core.

[0005] However, with the composite contact lens disclosed in Patent Document 1, it is difficult to obtain a satisfactory wearing feeling that the feeling of foreign matter during wearing is still large. As a result of examination and experiment by the present inventor, the foreign matter feeling during wearing is a boundary portion between a portion formed of a hard material (lens core) and a portion formed of a soft material (edge portion). Has come to be recognized as being caused by contact with the eyeball.

That is, in the composite contact lens disclosed in Patent Document 1, the edge of the outer peripheral edge of the lens core formed of a hard material is attached to the eyeball at the joint between the lens core and the edge. It will be contacted. When such an edge is brought into contact with a sensitive eyeball surface, it is still difficult to fully improve the feeling of wearing because a sense of a foreign body may cause a pain or the like to be detected.

[0007] By the way, in Patent Document 1, in order to avoid the occurrence of such a problem, the surface (rear surface) facing the cornea at the boundary between the lens core and the edge portion is configured by the same paraboloid. It is described. However, further research and experiments by the inventor have shown that the hard material that forms the lens core and the soft material that forms the edge of the lens core can be reduced even if the steps in the joint are sufficiently reduced during manufacturing by increasing the accuracy of processing and forming. Since the materials are different from each other, it is clear that there can be a feeling of foreign matter during wearing, especially at the joint of dissimilar materials.

That is, the lens core made of a hard material and the edge portion made of a soft material have different thermal expansion coefficients, swelling rates, elastic coefficients, and the like. Therefore, thermal expansion due to changes in temperature due to outside air temperature or body temperature in the wearing state, z thermal contraction, swelling due to tear absorption, etc., elastic deformation due to the action of external force on the lip, etc. However, even if there is a step in the joint between dissimilar materials, it is difficult to avoid the occurrence of a step under wearing conditions. Power! In addition, the friction coefficient is often different between the hard material forming the lens core and the soft material forming the edge. For these reasons, when wearing a contact lens, the joint of different materials is easily stimulated on the cornea, especially when the contact lens moves on the cornea so that the joint is caught on the cornea. May cause strong irritation. Therefore, On the rear surface of the contact lens, even if the lens core side and the edge side sandwiching the joint portion are configured on the same spherical surface with high accuracy at the time of processing, the joint portion must be brought into contact with the eyeball surface. It has been found that it is extremely difficult to avoid the feeling of foreign objects due to spills.

[0009] In addition, as shown in Patent Document 2 (Japanese Patent Laid-Open No. 48-66854), by covering the hard core layer portion with a soft surface layer portion, the surface portion that can be brought into contact with the eyeball surface Attempts have also been made to avoid pain and other foreign objects by making the joint material of a multi-material contact lens come into contact with the eyeball by unifying the material with a soft material. However, it is difficult to manufacture a multi-material contact lens having such a structure. In particular, in order to sufficiently supply oxygen to the cornea, it is desirable to use an oxygen-permeable material as the hard material. However, as shown in Patent Document 2, it is made of a hard material. If the core layer portion is embedded in the surface layer portion formed of a soft material, there is a problem that oxygen supply to the cornea due to gas permeation, which is an advantage of the oxygen permeable material, can hardly be expected.

[0010] Patent Document 1: Japanese Patent Laid-Open No. 49-120655

Patent Document 2: JP-A-48-66854

Disclosure of the invention

Problems to be solved by the invention

[0011] Here, the present invention has been made in the background as described above, and the problem to be solved is the excellent optical characteristics of the hard type contact lens and the excellent of the soft type contact lens. This is a multi-material contact lens that can achieve a high level of wearing comfort, and in particular, a new structure that can realize a better wearing feeling by reducing the feeling of foreign matter caused by the joint of different materials coming into contact with the eyeball surface. It is an object to provide multi-material contact lenses.

Means for solving the problem

Hereinafter, embodiments of the present invention made to solve such problems will be described. Note that the constituent elements employed in each aspect described below can be employed in any combination as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or descriptions thereof. It should be understood that the loading force is also recognized based on the inventive concept that can be grasped by those skilled in the art.

That is, in the first aspect of the present invention, predetermined optical characteristics are set in a multi-material contact lens having a central portion formed of a hard lens material and an outer peripheral portion force formed of a soft lens material. And forming a boundary between the central portion and the outer peripheral portion with respect to a peripheral portion formed on the outer peripheral side of the optical portion. Of the rear surface and the rear surface of the peripheral portion, the boundary between the central portion and the outer peripheral portion of the rear surface of the lens and the outer surface of the eyeball surface, compared to the rear surface on the near side of the eyeball that is positioned closer to the eyeball surface. The radius of curvature of the rear surface of the lens in the region where the boundary line is located is made different from the radius of curvature of the rear surface on the near side of the eyeball so that the separation distance becomes larger.

[0014] In the multi-material contact lens having a structure according to this embodiment, it is possible to avoid a pain or the like when wearing a foreign object that is likely to cause a problem at the boundary between the central portion and the peripheral portion, and to provide an excellent wearing feeling. Can be realized. That is, in a multi-material contact lens, a difference or the like occurs in the boundary line between the central portion and the outer peripheral portion due to the difference in the coefficient of thermal expansion, moisture content, or elastic modulus due to the difference in material between the central portion and the outer peripheral portion When wearing a foreign object feeling caused by a strong step touching the surface of the eyeball, pain or the like is likely to be a problem. However, in the multi-material contact lens according to this embodiment, the boundary between the central portion and the outer peripheral portion of the rear surface of the lens By sufficiently separating the field line from the surface of the eyeball, even if there is a step or the like at the boundary in the wearing state on the eye, it is possible to realize an excellent wearing feeling without causing pain if a foreign body feels.

[0015] Further, in the multi-material contact lens of this aspect, since the boundary surface of the material is formed at a position sufficiently deviated from the optical part to the outer peripheral side, the reflection and scattering of light rays at the boundary surface of the material, Problems such as flare caused by refraction can be effectively avoided.

[0016] In this aspect, preferably, the radius of curvature of the rear surface of the lens in the region where the boundary line is located is different from the radius of curvature of the surface of the eyeball facing the region in the direction of the radius of curvature. The value is set to be larger than the value of the difference between the radius of curvature of the above-mentioned rear surface on the near side of the eyeball and the radius of curvature of the surface of the eyeball positioned opposite thereto. [0017] In the present invention, at least one of the rear surfaces of the optical unit and the peripheral unit corresponding to the rear surface on the near side of the eyeball is substantially similar to the eyeball surface positioned close to the lens under wearing conditions. It is desirable to have a curved surface with a radius of curvature.

[0018] Furthermore, in the present invention, the separation distance between the rear surface of the optical part and the peripheral part and the eyeball surface may be set to be as small as substantially the same. In this case, the rear surfaces of the optical part and the peripheral part are all the rear surfaces on the eyeball proximity side.

[0019] In addition, according to a second aspect of the present invention, in the multi-material contact lens according to the first aspect, a curvature radius of an eyeball surface among a rear surface of the optical unit and a rear surface of the peripheral unit is determined. The radius direction of curvature of the boundary line between the central portion and the outer peripheral portion of the rear surface of the lens with respect to an extension line of the rear surface of the rear surface formed with a radius of curvature and having a smaller separation distance from the eyeball surface. Separation distance at: X is characterized as 0.01 mm ≤ x ≤ 0.25 mm.

[0020] In such a multi-material contact lens having a structure according to this aspect, the boundary line on the rear surface of the lens can be stably separated by setting the value of X appropriately. . As a result, it is possible to more effectively improve the wearing feeling of the contact lens.

[0021] In addition, according to a third aspect of the present invention, in the multi-material contact lens according to the first or second aspect, a plurality of lens rear surfaces of the peripheral portion have a plurality of curvature radii different from each other in the radial direction. A curved surface region is formed, and an outer peripheral side peripheral portion having a curvature different from the region is formed outside the inner peripheral side peripheral portion where the boundary line is located.

[0022] In the multi-material contact lens having a structure according to the present embodiment as described above, by setting the rear surface curvature of the peripheral portion in a plurality of stages, for example, the contact lens required for the peripheral portion in the peripheral portion on the outer peripheral side. It is possible to sufficiently position the boundary line at the peripheral portion on the inner peripheral side and the surface force of the eyeball sufficiently while ensuring functions such as wearing stability sufficiently.

[0023] Further, according to a fourth aspect of the present invention, in the multi-material contact lens according to the third aspect, the rear surface of the optical unit has a radius of curvature of the surface of the eyeball rather than the rear surface of the outer peripheral side peripheral part. So that the distance from the eyeball surface is smaller. In addition, the rear surface of the inner peripheral side peripheral portion is formed so as to smoothly connect the rear surface of the optical portion and the rear surface of the outer peripheral side peripheral portion in the radial direction.

[0024] Further, according to a fifth aspect of the present invention, in the multi-material contact lens according to the third aspect, the rear surface of the outer peripheral side peripheral portion has a radius of curvature of the eyeball surface relative to the rear surface of the optical portion. So that the distance from the surface of the eyeball becomes smaller, and the rear surface of the peripheral portion on the outer peripheral side and the rear surface of the optical unit are smoothly connected in the radial direction. A rear surface of the inner peripheral side peripheral portion is formed.

[0025] In the fourth and fifth aspects, smoothly connecting the rear surface of the optical unit and the rear surface of the outer peripheral side in the radial direction means that the rear surface of the optical unit and the outer peripheral side of the optical unit in the radial cross section. In any case, the rear surface of the inner peripheral side peripheral portion is constituted by a curved surface connected with a common tangent at each boundary. As the shape of the curved surface, various smooth curved surface shapes such as a multi-degree curve such as a quadratic curve and a cubic curve, a trigonometric function, and a conic curve can be adopted. By adopting such a rear surface shape, stimulation to the cornea at the boundary part of the optical part and the peripheral part other than the boundary line of different materials can be suppressed, and a better wearing feeling can be realized.

[0026] Further, a sixth aspect of the present invention is the multi-material contact lens according to any one of the third to fifth aspects, wherein a rear surface of the optical part and a rear surface of the inner peripheral side peripheral part are provided. The rear surface of the outer peripheral side peripheral portion is formed by a concave curved surface, and the rear surface of the inner peripheral peripheral portion has a larger radius of curvature than the rear surface of the optical portion. The rear surface of the outer peripheral side peripheral portion has a larger radius of curvature than the rear surface of the inner peripheral side peripheral portion.

[0027] By adopting such a rear surface shape, the optical part and the outer peripheral part are skillfully formed in the cornea center of the eyeball and in the vicinity of the sclera located at the outer peripheral side and having a larger radius of curvature than the central cornea. It is possible to advantageously secure a separation distance between the boundary line located on the inner peripheral side and the eyeball surface while improving the stability of the contact lens in the wearing state so that the contact lens is closely aligned. .

[0028] Further, according to a seventh aspect of the present invention, in the multi-material contact lens according to the first or second aspect, the lens rear surface is opened at a portion where the boundary line is located. It is characterized in that a concave groove is formed extending around the entire circumference in the circumferential direction, and the boundary line is positioned on the inner surface of the concave groove.

[0029] In the multi-material contact lens having the structure according to this aspect, the boundary line on the rear surface of the lens is located on the inner surface of the concave groove. It is possible to increase the separation state of the eyeball surface force at the boundary line by actively separating only the formation area of the boundary line while keeping the shape as close as possible to the surface. In addition, it is desirable that the opening edge of the concave groove has a shape that is smoothly connected to the rear surface of the lens in the peripheral portion.

[0030] Further, an eighth aspect of the present invention is the multi-material contact lens according to the seventh aspect, wherein the width dimension of the concave groove is W force 0.1 mm≤W≤3. Omm, And the depth dimension of this ditch | groove: D force 0.005mm <= D <= 0.15mm, It is characterized by the above-mentioned.

[0031] By adopting the shape of the concave groove according to this embodiment, the concave groove is formed without greatly impairing the function and strength of the optical part and the peripheral part, and the contact of the boundary line to the eyeball surface is prevented. This can be advantageously prevented.

[0032] Further, a ninth aspect of the present invention is the multi-material contact lens according to any one of the first to eighth aspects, wherein the Young's modulus of the hard lens material forming the central portion is used. Is characterized in that the Young's modulus of the soft lens material forming the outer peripheral portion is 0.2 MPa to 3 MPa.

[0033] In such a multi-material contact lens having a structure according to this embodiment, the shape stability of the optical part can be exhibited better, more excellent optical characteristics can be realized, and the flexibility of the outer peripheral part can be realized. Is sufficiently ensured, and a better wearing feeling can be realized. More preferably, the hard lens material forming the central portion has a Young's modulus of 100 MPa to 1500 MPa, and the soft lens material forming the outer peripheral portion has a Young's modulus of 0.2 MPa to 2 MPa.

[0034] Further, according to a tenth aspect of the present invention, in the multi-material contact lens according to any one of the first to ninth aspects, the central portion is formed of an oxygen-permeable hard lens material. It is characterized by that.

[0035] Further, an eleventh aspect of the present invention relates to any one of the first to tenth aspects. The multi-material contact lens is characterized in that the outer peripheral portion is formed of a hydrous soft lens material.

[0036] In the multi-material contact lens having the structure according to the tenth aspect or the eleventh aspect, the amount of movement of the contact lens on the cornea is caused by oxygen or tear fluid that permeates the lens. Even when is small, oxygen can be supplied to the cornea more advantageously.

[0037] Further, a twelfth aspect of the present invention is the multi-material contact lens according to any one of the first to eleventh aspects, wherein the peripheral part of the peripheral part is more peripheral than the boundary line. In addition, a circumferential groove that is open on the rear surface side of the lens and extends continuously over the entire circumference in the circumferential direction is formed.

[0038] In such a multi-material contact lens having a structure according to this embodiment, tear fluid exchange in the tear film on the cornea can be advantageously performed, and oxygen supply to the cornea is advantageously realized. I can do it.

The invention's effect

As is apparent from the above description, in the multi-material contact lens having a structure according to the present invention, the joint between the central portion and the peripheral portion that cause a foreign object sensation when mounted on the eyeball surface is provided. Eye surface force Since the eye surface is actively separated, the feeling of foreign matter can be reduced and an excellent wearing feeling can be exhibited.

[0040] In addition, since the boundary surface between the hard lens material and the soft lens material is positioned at the peripheral portion where the optical portion is separated from the outer peripheral side by a predetermined distance, for example, the thermal expansion coefficient is swollen. When stress or strain occurs on the boundary surface of the material due to differences in refractive index, elasticity, etc., or when scattering or flare occurs on the boundary surface due to differences in refractive index, etc. However, the adverse effects on the optical characteristics caused by them can be reduced or avoided. Brief Description of Drawings

FIG. 1 is a longitudinal cross-sectional explanatory view showing a multi-material contact lens as a first embodiment of the present invention.

FIG. 2 is a front view of the multi-material contact lens shown in FIG.

FIG. 3 is a rear view of the multi-material contact lens shown in FIG. 1.

FIG. 4 is a longitudinal sectional view illustrating a multi-material contact lens as a second embodiment of the present invention. It is.

V] is a longitudinal cross-sectional explanatory view showing a multi-material contact lens as a third embodiment of the present invention.

FIG. 6 is a longitudinal cross-sectional explanatory view showing a multi-material contact lens as another embodiment of the present invention.

FIG. 7 is a longitudinal cross-sectional explanatory view showing a multi-material contact lens as a fourth embodiment of the present invention.

Explanation of symbols

[0042] 10 contact lenses

12 Corneal surface

16 Optics

18 Peripheral

22 Rear of optics

38 Rear surface of the second periphery

56 Center part

58 Perimeter

60

62 lines

BEST MODE FOR CARRYING OUT THE INVENTION

[0043] Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, contact lens 10 force as a first embodiment of the present invention is shown by a longitudinal sectional view in FIG. 1, a front view in FIG. 2, and a rear view in FIG. The contact lens 10 has a substantially spherical shell shape as a whole, and is attached to the surface 12 of the cornea of the eyeball as is well known. In the contact lens 10 of the present embodiment, the lens central axis 14 is the optical axis, and the shape of the rotating body around the lens central axis 14 is shown in FIG. Only the longitudinal section is shown. More specifically, in the contact lens 10 that is strong, a circular optical portion 16 is formed in the center portion in a front view as in the conventional case, and a circle around the optical portion 16 is formed. A ring-shaped peripheral portion 18 is formed. An edge portion 19 is formed on the outer peripheral edge portion of the peripheral portion 18.

The optical unit 16 has an optical unit front surface 20 and an optical unit rear surface 22. The rear surface 22 of the optical unit is centered on the lens rear axis (right side in FIG. 1) on the lens center axis 14 so that it is substantially similar to the shape of the corneal surface 12 to be mounted. Is set to be a base curve surface having a concave longitudinal section shape with an appropriate radius of curvature: r.

BOZ

As a result, the size of the gap 24 formed between the rear surface 22 of the optical part 22 and the surface 12 of the cornea under the wearing state of the contact lens 10 is substantially constant over the entire force t.

0

The lens action due to the tear film formed is reduced or avoided.

[0047] Note that the longitudinal cross-sectional shape of the base curve surface (rear surface of the optical part) 22 is set in consideration of the shape of the wearer's cornea, wearing conditions, and the like. For example, radius of curvature: r

Various curved concave surfaces such as a circular arc shape with a constant BOZ and a conical curved shape with a radius of curvature: r varied in the radial direction

BOZ

The shape can be adopted as appropriate.

[0048] On the other hand, the front surface 20 of the optical part of the contact lens 10 is designed as a curved surface shape that can provide a target lens power in cooperation with the base force groove surface 22 set as described above. Specifically, the center of curvature is set behind the lens on the lens center axis 14 to form a curved convex surface having a longitudinal sectional shape with an appropriate radius of curvature: r. In addition, this

FOZ

The front surface (front curve surface) 20 of the optical unit is determined in consideration of the shape of the base curve surface 22, the required lens power, wearing conditions, and the like. For example, an arc shape with a constant radius of curvature: r

FOZ

In addition to the shape, various curved convex shapes such as a conical curve shape with a radius of curvature r varying in the radial direction

FOZ

Etc. may be adopted as appropriate.

[0049] The optical part 16 formed by the front and rear optical parts 20 and 22 is an area where an optical effect on the eyes of the wearer is expected. In general, this boundary can be regarded as a change point of curvature on the longitudinal section on the front surface of the lens and the rear surface of the lens, respectively. However, for example, when the lens surface of the optical unit is designed with a longitudinal cross-sectional shape that gradually changes in the radial direction, or the force boundary is in the radial direction. The boundary between the optical part and the peripheral part on the lens front and rear surfaces is linearly shaped (line), such as when it is formed with a connection area that smoothly connects the optical part and the peripheral part between the lens front and rear surfaces. ) Is not necessarily clear. Incidentally, in this embodiment shown in FIG. 1, the curvature radius of the optical part 16 and the peripheral part 18 are different on both the front surface and the rear surface of the lens.

On the other hand, the peripheral portion 18 includes a first peripheral portion 26, a second peripheral portion 28, and a third peripheral portion 30. These three peripheral portions 26, 28, and 30 spread in a concentric ring shape centering on the lens central axis 14 in a front view, and are integrally formed sequentially from the inner peripheral side.

[0051] In the present embodiment, the first peripheral portion 26 formed integrally and continuously on the outer peripheral side of the optical portion 16 has a front surface (first peripheral portion front surface) 32 having a larger radius of curvature than the optical portion front surface 20. : r

Or) and a spherical surface! Also, the rear surface of the first peripheral part 26 (the rear of the first peripheral part

FOZ

Surface) 34 is a spherical surface having a larger radius of curvature: r (> r) than the optic rear surface 22

BPZ1 BOZ

ing. In particular, in the present embodiment, the radius of curvature of the rear surface of the first peripheral portion is set to be larger than the radius of curvature of the front surface of the first peripheral portion (r ≥r).

BPZ1 FPZ1

[0052] Further, the second peripheral portion 28 formed integrally and continuously on the outer peripheral side of the first peripheral portion 26 has a front surface (front surface of the second peripheral portion) 36 having a larger curvature than the front surface 32 of the first peripheral portion. Radius: r (> r

FPZ2 FP

) Has a spherical surface. Furthermore, the rear surface of the second peripheral portion 28 (the rear surface of the second peripheral portion

Z1

38 is a sphere having a larger radius of curvature: r (> r) than the first peripheral rear face 34

BPZ2 BPZ1

It is considered as a surface.

[0053] It should be noted that the first junction 50, which is a connecting portion between the outer peripheral edge of the optical part 16 and the inner peripheral edge of the first peripheral part 26, the outer peripheral part of the first peripheral part 26 and the second peripheral part 28 The second junction 52, which is a connection portion with the inner peripheral edge, is smoothly connected on the front and rear surfaces. Specifically, the front and back surfaces are smooth so as to have a common tangent, such as a multi-degree curve such as a quadratic curve or a cubic curve, a trigonometric function, a conic curve, or the like so that there is no break point in the longitudinal section. Connected to and hope to be.

[0054] Also, the thickness dimension of the first junction 50: the thickness of the second junction 52 compared to T

1

Dimensions: T should be TX O. 5 <T <Τ. Cover and Τ ≥Τ, The feeling of wearing tends to be poor due to the stimulation to the body. On the other hand, if T ≤Τ Ο Ο.

twenty one

It tends to be defective, and the surface shape tends to be distorted, resulting in poor wearing feeling. The third junction 54, which is a connecting portion between the outer peripheral edge of the second peripheral portion 28 and the inner peripheral edge of the third peripheral portion 30, is 0.05 mm to obtain a good wearing feeling and sufficient strength. A thickness of 0. 25 mm is desirable.

[0055] Furthermore, the third peripheral portion 30 integrally formed continuously on the outer peripheral side of the second peripheral portion 28 has a longitudinal cross-sectional shape shown in FIG. Linearly, the outer peripheral edge force of the second peripheral portion 28 also extends in the direction approaching each other. Thereby, the vertical cross-sectional shape of the third peripheral portion 30 is tapered.

Furthermore, an edge portion 19 is integrally formed continuously on the outer peripheral side of the third peripheral portion 30. The edge portion 19 has a substantially semicircular vertical cross-sectional shape, and its outer peripheral surface smoothly smoothes the front surface (third peripheral portion front surface 40) and rear surface (third peripheral portion rear surface 42) of the contact lens 10. It is connected to.

Thus, as shown in FIG. 1, in the contact lens 10 of this embodiment, the rear surface 22 of the optical unit is substantially matched with the shape of the surface 12 of the eyeball cornea to be worn (exactly Is set so as to have a substantially similar shape across the minute gap 24 that becomes the tear film), and the rear surfaces 34 and 38 of the peripheral portion 18 are lifted up with reference to the rear surface 22 of the optical unit. (Separated forward). That is, the first peripheral rear surface 34 is lifted up (separated) relatively rapidly with respect to the extension line 44 of the optical rear surface 22, and the first peripheral portion rear surface 34 is The rear surface 38 of the two peripheral parts lifts up relatively slowly. Further, the rear surface 42 of the third peripheral portion is lifted up further by the extended linear force of the second peripheral portion 38.

As is apparent from this, in the present embodiment, the rear surface 22 of the optical unit is the rear surface on the eyeball proximity side. The curvature radius (r) of the first peripheral rear surface 34 where the boundary surface (60) described later is located is set to be larger than the curvature radius (r) of the rear surface of the optical unit.

BPZ1 BOZ

-ing

[0059] As a result, as illustrated in FIG. 1, when the contact lens 10 is worn, the rear surface 22 of the optical part is superimposed closest to the surface 12 of the center of the cornea of the eyeball. It has become. In addition, the rear surface 34 of the first peripheral portion is relatively large from the surface 12 of the cornea. It is designed to be spaced apart. Furthermore, the rear surface 38 of the second peripheral portion spreads gently along the outer peripheral portion of the cornea, the ring portion, or the heel of the cornea having an increased curvature radius, and the surface 12 of the joint portion. In addition, the rear surface 42 of the third peripheral part is directed toward the outer peripheral side with respect to the eyeball surface 12 so that the gap 24 between the third peripheral part and the surface 12 of the eyeball is opened toward the outer peripheral side to promote tear exchange. They are separated in an expanded manner.

[0060] As described above, the contact lens 10 having a substantially spherical shell shape as a whole is formed of two different materials. Specifically, a circular region located in the center in the axial front view (see FIG. 1) is a central portion 56 formed of a hard material. On the other hand, a region surrounding the central portion 56 and having an annular shape when viewed from the front in the axial direction is an outer peripheral portion 58 formed of a soft material. That is, the central portion 56 and the outer peripheral portion 58 have a coaxial rotating body shape with the lens central axis 14 as the center.

[0061] Here, as the hard material forming the central portion 56, a material having a Young's modulus: Y force of 3 MPa≤Y≤3000 MPa is suitably employed. On the other hand, as the soft material forming the outer peripheral portion 58, a material having a Young's modulus: Y force of 0.2 MPa ≤ Y ≤ 3 MPa is preferably used.

P P

Used. More preferably, 100MPa≤Y ≤1500MPa, 0. 2MPa≤Y ≤2MPa and c p

It is.

[0062] More specifically, as the hard material forming the central portion 56, conventionally known various hard contact lens materials can be employed, for example, methyl metatalylate (MMA) or the like can be employed. Preferably, oxygen permeable node contact lens materials such as siloxane metatalate (SMA) and fluorometatalate (FMA) are employed. In addition, as the soft material forming the outer peripheral portion 58, various known materials for soft contact lenses can be used. In addition, any silicon-containing hydrous or non-hydrous soft contact lens material can be used.

[0063] The central portion 56 and the outer peripheral portion 58 are defined by a circular boundary surface 60 extending around the lens central axis 14 at the radial intermediate portion of the contact lens 10. The boundary surface 60, which is a joint portion of this dissimilar material, is positioned at the first peripheral portion 26. In particular, in this embodiment, the boundary surface 60 is positioned at a substantially central portion in the radial direction (width direction) of the first peripheral portion 26. Set It has been.

Accordingly, the boundary surface 60 is exposed as a boundary line on the first peripheral portion rear surface 34 on the rear surface of the lens. In this embodiment, the boundary surface 60 is a force that is a cylindrical surface substantially parallel to the lens central axis 14. The boundary surface 60 is a taper surface inclined with respect to the lens central axis 14. There may be.

Further, the position of the boundary surface 60 is set according to the wearer's corneal diameter, pupil diameter, corneal shape, etc., including the size of the optical part and the peripheral part, and is not limited. However, the following are examples of typical design standard values.

(1) Contact lens 10 outer diameter: DIA

9. 0mm≤DIA≤15. Omm

(2) Optical part front 20 outer diameter: FOZD

6. 0mm≤FOZD≤10. Omm

(3) Outer diameter of optical unit rear 22: BOZD

6. 5mm≤BOZD≤10. Omm

(4) Radius of curvature of the rear 22 of the optical part: BC

6. 5mm≤BC≤9. 3mm

(5) Front width 32 of the first peripheral part: FP1W

0. 5mm≤FPlW≤2. 5mm

(6) Width of first peripheral rear 34: BP1W

0. 5mm≤BPlW≤2.Omm

(7) Diameter dimension of interface 60: MDIA

4. Omm≤MDIA≤13.5 mm

(8) MDIAZDIA value

0. 4≤MDIA / DIA≤0.9

[0066] Incidentally, the contact lens 10 having a composite structure including two kinds of materials, that is, the central portion 56 formed of the hard material as described above and the outer peripheral portion 58 formed of the soft material, is obtained by the following method, for example. Can be manufactured.

[0067] First, as disclosed in Japanese Patent Laid-Open No. 56-56313, a water-soluble inert substance is previously prepared. Thick disc-shaped lens blanks are formed by polymerization using a soft material prepared by blending the materials. Next, a hole penetrating substantially the center of the lens brand is axially formed by a mechanical calorie or the like to process the lens blank into a substantially annular shape. Thereafter, a gas-permeable hard material is filled into a through-hole formed in a lens material such as a soft material, and polymerization molding is performed.

[0068] Thereby, it is possible to obtain a lens blank in which the center is formed of a hard material and the outer periphery is integrally formed of a soft material. If such a lens blank can be obtained, then, according to a conventionally known processing apparatus and processing method, cutting is performed on the lens blanks to be processed, and the contact lens 10 is processed into a target shape. .

[0069] Further, the obtained contact lens 10 is immersed in treated water having an appropriate osmotic pressure, and the water-soluble inert substance blended in the soft material is replaced with water. As a result, the soft material that has been made hard at the time of processing can be softened by containing water without changing the volume or shape. Thus, the target contact lens 10 having the composite structure as described above can be obtained.

[0070] It should be noted that the manufacturing method of the contact lens having the structure according to the present invention is not particularly limited, and various manufacturing methods can be employed depending on the material to be used. For example, a central part 56 made of a hard material and an outer peripheral part 58 made of a soft material are manufactured separately from each other by an appropriate method such as a spin casting method, a mold forming method, or a cutting method, and then fixed together. By integrating them, it is also possible to obtain a target contact lens 10 having a composite structure. It is to be noted that an adhesive may be used for fixing the central portion 56 and the outer peripheral portion 58. In this case, an adhesive layer is interposed on the boundary surface 60 which is a joint surface.

[0071] Thus, in the contact lens 10 having the above-described structure, the optical portion rear surface 28 is superimposed closest to the cornea surface 12 in the wearing state on the eye, and the second The rear surface 38 of the peripheral portion 28 is superimposed on the outer peripheral portion of the corneal surface 12 and so on along the surface. As a result, the entire force of the contact lens 10 can be stably held at a predetermined position on the cornea of the eye based on the excellent positioning action on the cornea by the second peripheral portion 28 made of a soft material. . In particular, the optical part made of hard material 16 Based on the excellent optical characteristics of the eye, the intended corrective action is stably exerted on the eye optical system.

[0072] Further, since the outer peripheral portion 58 of the contact lens 10 including the second peripheral portion 28 is formed of a soft material, the excellent optical characteristics of the optical portion 16 formed of a hard material are obtained. An excellent feeling of wearing can be exhibited while securing the property.

[0073] In particular, by employing an oxygen-permeable material as the hard material forming the optical part 16, the burden on the eyes during wearing can be reduced, and the feeling of wearing can be further improved. In addition, in the present embodiment, since the rear surface 42 of the third peripheral portion 30 is directed toward the outer periphery and is separated from the surface 12 such as the cornea, the shape is such that the contact lens 10 and the cornea are expanded outward. As a result, the tear fluid exchange from the outside is more efficiently realized with respect to the tear film formed in the gap 24, and this tear fluid exchange action also reduces the burden on the eyes. The wearing feeling is further improved.

On the other hand, the rear surface 34 of the first peripheral portion 26 is positioned away from the corneal surface 12 as it goes from the inner peripheral edge to the outer peripheral side when the contact lens 10 is worn. As a result, the boundary line (boundary surface) 60 located substantially at the center in the width direction of the rear surface 34 of the first peripheral portion is positioned away from the corneal surface 12 with a large gap.

[0075] Therefore, even when a step or unevenness occurs on the boundary line 62 of the first peripheral rear surface 34 due to temperature strain, stress strain, or the like, contact with the corneal surface 12 is effectively reduced or reduced. Can be avoided. As a result, irritation to the cornea is suppressed, and the bad feeling of wearing due to the presence of the demarcating boundary 62 can be avoided.

In addition, the boundary surface 60 between the hard material forming the optical portion 16 and the soft material forming the peripheral portion 18 is moved outward from the first junction 50 that is the boundary between the optical portion 16 and the peripheral portion 18. Since it is provided at the position, the adverse effect on the optical system due to the scattering of light rays at the powerful boundary surface 60 can be suppressed extremely effectively. As a result, the target optical characteristic force optical part 16 can be more stably and highly accurately exhibited.

[0077] The gap dimension between the boundary line 62 and the cornea surface 12 on the first peripheral rear surface 34 (separation distance in the radius direction of curvature of the first peripheral rear surface 34): X is 0.01 mm or more. More preferably, it is set to 0.01 mm ≤ X ≤ 0.25 mm. Cover and take the gap dimension Method: If X is too small, contact with the cornea due to the boundary line 62 may cause a problem.On the other hand, if the gap dimension is too large, the lift amount from the corneal surface 12 of the peripheral portion 18 (separation dimension) This is because there is a risk that the feeling of wearing may be reduced when the method is large.

[0078] In order to realize such a separation distance: X, when designing the rear surface of the contact lens 10, for example, in the radial longitudinal section, the extension line 44 of the rear surface (BC) of the optical unit Separation distance from the boundary line 62 on the first peripheral rear surface 34: X is set to 0.01 mm ≤ X ≤ 0.25 mm

0 0

More preferably, 0.05 mm ≤ X ≤ 0.15 mm, more preferably 0.09 mm

0

≤X ≤0.

0

Next, FIG. 4 shows a contact lens 64 as a second embodiment of the present invention. In the following description, members or parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

[0080] More specifically, the contact lens 64 according to the present embodiment has a substantially spherical shell shape as a whole in the same manner as the contact lens 64 according to the first embodiment. A circular optical part is formed in the central part, and an annular peripheral part 68 is formed around the optical part 66. An edge portion 19 is formed on the outer peripheral edge of the peripheral portion 68.

The optical unit 66 in the present embodiment has an optical unit front surface 70 and an optical unit rear surface 72. In particular, in this embodiment, the radius of curvature of the rear surface 72 of the optical part: r the radius of curvature of the corneal surface 12

BOZ

The size of the gap 74 between the rear surface 72 of the optical unit 72 and the corneal surface 12 is reduced while the center side of the rear surface 72 of the optical unit is gradually separated from the corneal surface 12 to be mounted. It gradually grows toward the center!

[0082] In the optical unit of the present embodiment, preferably, in the radial longitudinal section, an extension line 75 of the optical unit rear surface 72 at the center of the contact lens 64 and a second peripheral rear surface (86) described later is 75. Separation distance: L is 0.02mm≤L≤0.2 mm, more preferably 0.05mm ≤L≤0.15mm, more preferably 0.1mm≤L≤0.12mm It is said. If it is covered and L is too small, the central part of the optic rear surface 72 may come into direct contact with the corneal surface 12 to cause damage to the eyeball, while L is too large. And the thickness of the tear film formed between the optic rear surface 72 and the corneal surface 12 is increased. Since the amount of movement of the lens 64 on the cornea becomes larger than necessary, the lens is liable to be displaced or lifted. In addition, when the tear film thickness is increased, the optical properties may be adversely affected by the lens effect of the tear film.

[0083] As the specific shapes of the optical unit front surface 70 and the optical unit rear surface 72 in this embodiment, various shapes shown in the first embodiment can be similarly employed. Further, the boundary between the optical part 66 and the peripheral part 68 is the same as described in the first embodiment. In particular, in this embodiment, the radius of curvature r of the front surface 70 of the optical unit is light.

FOZ

Radius of curvature of the rear face of the faculty 72: The radius of curvature is larger than r.

BOZ

The optical part 66 becomes thicker.

On the other hand, the peripheral portion 68 includes a first peripheral portion 76, a second peripheral portion 78, and a third peripheral portion 30. These three peripheral portions 76, 78, and 30 spread in a concentric ring shape around the lens central axis 14 in a front view, and are integrally formed sequentially from the inner peripheral side.

[0085] The first peripheral portion 76 continuously formed integrally with the outer peripheral side of the optical portion 66 has a front surface (first peripheral portion front surface) 80 having the same radius of curvature as the optical front surface 70: r (= r ) Spherical surface

FPZ1 FOZ

It is said that. Further, the rear surface (first peripheral portion rear surface) 82 of the first peripheral portion 76 is a spherical surface having the same radius of curvature: r (= r) as the optical portion rear surface 72. In particular, this embodiment

BPZ1 BOZ

In this state, the radius of curvature of the front surface 80 of the first peripheral portion is set to be equal to or smaller than the radius of curvature of the rear surface 82 of the first peripheral portion (r ≥r).

FPZ1 BPZ1

[0086] Further, the second peripheral portion 78 continuously formed integrally with the outer peripheral side of the first peripheral portion 76 has a front surface (second peripheral portion front surface) 84 having a larger curvature than the first peripheral portion front surface 80. Radius: r (> r

FPZ2 FP

) Has a spherical surface. Furthermore, the rear surface of the second peripheral portion 78 (the rear surface of the second peripheral portion

Z1

) 86 is a sphere with a larger radius of curvature: r (> r) than the first peripheral rear face 82

BPZ2 BPZ1

It is considered as a surface. In particular, in the present embodiment, the second peripheral rear surface 86 is on the lens central axis 14 so that the second peripheral rear surface 86 is substantially similar to the corneal surface 12 to be mounted under the lens wearing condition. The center of curvature is set on the right. As a result, the size of the gap 74 formed between the rear surface 86 of the second peripheral portion 86 and the corneal surface 12 under the wearing state of the contact lens 64: t

1

It is almost constant throughout 1S. Note that the third peripheral portion 68 and the edge portion 19 in the present embodiment are substantially the same as those in the first embodiment, and thus description thereof is omitted here. Also, the first junction 50, which is the connection part between the optical part 66 and the first peripheral part 76, the second junction 52, which is the connection part between the first peripheral part 76 and the second peripheral part 78, the second peripheral part 78 and the third peripheral part. Since the third junction 54, which is the connecting portion of the peripheral portion 68, is substantially the same as that of the first embodiment, description thereof is omitted.

Accordingly, as shown in FIG. 4, in the contact lens 64 of the present embodiment, the second peripheral portion 78 is substantially matched with the shape of the surface 12 of the eyeball cornea to be worn (exactly In addition, the rear surface of the optical part 72 and the first peripheral part are defined with reference to the rear surface 86 of the second peripheral part. Rear part 82 and third rear part 42 are lifted up (separated forward). As is clear from this, in the present embodiment, the rear surface 86 of the second peripheral portion is the rear surface on the eyeball proximity side.

As a result, as illustrated in FIG. 4, when the contact lens 64 is worn, the second peripheral portion with respect to the outer peripheral portion of the cornea and the surface 12 of the portion such as the limbus or the conjunctiva in the eyeball. The rear face 86 is closest to overlap. Further, the rear surface 72 of the optical part and the rear surface 82 of the first peripheral part are positioned sufficiently separated from the surface 12 of the cornea. Further, the gap between the rear surface 42 of the third peripheral portion and the eyeball surface 12 is opened toward the outer peripheral side, so that the tear fluid exchange is promoted, and the posterior surface 42 expands toward the outer peripheral side with respect to the cornea surface 12. Openly spaced.

[0090] As described above, the contact lens 64 having a substantially spherical shell shape as a whole is formed of two different materials. Specifically, a circular region located in the center in the axial front view is a central portion 88 formed of a hard material. On the other hand, a region surrounding the central portion 88 and having an annular shape when viewed from the front in the axial direction is an outer peripheral portion 90 formed of a soft material. That is, the central portion 88 and the outer peripheral portion 90 have a coaxial rotating body shape centered on the lens center axis 14.

[0091] Note that the specific materials and the like of the central portion 88 and the outer peripheral portion 90 in the present embodiment are substantially the same as those in the first embodiment, and therefore a detailed description is given to avoid redundant description. Is omitted. The central portion 88 and the outer peripheral portion 90 are defined by a circular boundary surface 92 extending around the lens central axis 14 in the radial intermediate portion of the contact lens 64. The boundary surface 92, which is a joint portion of the different materials, is positioned at the first peripheral portion 76, and particularly in the present embodiment, is positioned at the substantially central portion in the radial direction (width direction) of the first peripheral portion 76. It has been tightened.

Thereby, the boundary surface 92 is exposed as a boundary line 94 on the first peripheral portion rear surface 82 on the rear surface of the lens. In the present embodiment, the boundary surface 92 is a tapered surface inclined with respect to the lens central axis 14.

[0094] Note that the gap dimension between the boundary line 94 and the cornea surface 12 on the first peripheral rear surface 82 (separation distance in the radius direction of curvature of the first peripheral rear surface 34): X is the same as that in the first embodiment. In order to appropriately obtain the dimensional range as shown, when designing the rear surface of the contact lens 64, the boundary line 94, which is the rear side end of the boundary surface 92, and the second peripheral rear surface 86 in the radial longitudinal section. Distance from extension line: X force, preferably 0.01 mm ≤ X ≤ 0.25 mm

0 0

. More preferably, X is 0.05 mm ≤ X ≤ 0.15 mm, and more preferably

0 0

Is set to 0.09 mm ≤ X ≤ 0.12 mm. Cover, X force, too much, the boundary line 94

0 0

While it is difficult to maintain a stable distance from the corneal surface 12, X is too large

0

As a result, the thickness of the tear film increases and the amount of movement of the lens increases, so that the correction of visual acuity may not be performed stably, and the feeling of wearing due to the contact of the boundary line 94 with the eyelid may be poor. Wrinkles tend to be a problem.

[0095] The position of the boundary surface 92 is set according to the wearer's corneal diameter, pupil diameter, corneal shape, etc., including the size of the optical part and the peripheral part, and is not limited. However, the following are examples of general design standard values.

(1) Contact lens 10 outer diameter: DIA

9. 0mm≤DIA≤15. Omm

(2) Optical part front 20 outer diameter: FOZD

6. 0mm≤FOZD≤10. Omm

(3) Outer diameter of optical unit rear 22: BOZD

6. 5mm≤BOZD≤10. Omm (4) Radius of curvature of the rear 22 of the optical part: BC

6. 5mm≤BC≤9. 3mm

(5) Front width 32 of the first peripheral part: FP1W

0. 5mm≤FPlW≤2. 5mm

(6) Width of first peripheral rear 34: BP1W

0. 5mm≤BPlW≤2. 5mm

(7) Diameter dimension of interface 60: MDIA

4. 0mm≤MDIA≤13.5mm

(8) MDIAZDIA value

0. 4≤MDIA / DIA≤0.9

It should be noted that, particularly in the present embodiment, in the radial longitudinal section, the radius of curvature of the second peripheral rear surface 86: r force The radius of curvature of the optical rear surface 72: r (BC): r +0.3 mm ≤r

BPZ2 BOZ BOZ BPZ

≤r + 2.0 mm, more preferably r +0.9 mm≤r

2 BOZ BOZ BPZ2

≤r + 1.5 and 5mm. That is, the radius of curvature of the second peripheral rear face 86: r force

BOZ BPZ2

6.8 mm≤r ≤11.3 mm, more preferably 7.4 mm≤r ≤10.8 mm.

BOZ BPZ2 Cover and radius of curvature of second peripheral back 86: If r is too small,

BPZ2

If the lens is easy to be adsorbed, there is a risk that it may be difficult to remove it. On the other hand, if r is too large, the outer peripheral side portion of the second peripheral portion 78 is separated from the surface 12 of the cornea.

BPZ2

Due to floating or the like, the amount of movement of the contact lens 64 increases, and there is a possibility that it is difficult to stably fix the positioning.

[0097] The contact lens 64 having the structure according to the present embodiment can exhibit the same excellent effect as that of the first embodiment.

FIG. 5 shows a contact lens 96 as a third embodiment. In the following description, members or portions that are substantially the same as those in the first or second embodiment are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

[0099] More specifically, the contact lens 96 that is effective in the present embodiment has a substantially spherical shell shape as a whole in substantially the same manner as in the first embodiment, and has a circular shape in the central portion in a front view. An optical part is formed, and an annular peripheral part 98 is formed around the optical part 66. It is. An edge portion 19 is formed on the outer peripheral edge portion of the peripheral portion 98.

[0100] The optical unit 16 in the present embodiment is substantially the same as that in the first embodiment, and thus detailed description thereof is omitted here.

On the other hand, the peripheral portion 98 is composed of a first peripheral portion 100 and a second peripheral portion 102. These two peripheral portions 100 and 102 spread in a concentric annular shape centering on the lens central axis 14 in a front view, and are integrally formed by successively connecting inner peripheral side forces.

[0102] The first peripheral portion 100 formed integrally and continuously on the outer peripheral side of the optical unit 16 has a front surface (first peripheral front surface) 104 having the same radius of curvature as the optical unit front surface 20: r (= r ) With ball

FPZ1 FOZ

It is a surface. Further, the rear surface (first peripheral portion rear surface) 106 of the first peripheral portion 100 is a spherical surface having the same radius of curvature: r (= r) as the optical portion rear surface 22. In particular, books

BPZ1 BOZ

In the embodiment, the radius of curvature of the front surface 104 of the first peripheral portion is set to be approximately the same as the radius of curvature of the rear surface 106 of the first peripheral portion (r = r;).

FPZ1 BPZ1

[0103] The second peripheral portion 102 formed integrally and continuously on the outer peripheral side of the first peripheral portion 100 has a front surface (front surface of the second peripheral portion) 108 on the lens central axis 14 and the rear of the lens ( While the center of curvature is set on the right side in Fig. 5, the rear surface of the second peripheral portion 102 (the rear surface of the second peripheral portion) 110 is the front of the lens on the lens center axis 14 (left side in Fig. 5). As a whole, the second peripheral portion 102 gradually becomes thinner as it is directed toward the outer peripheral side.

Note that the edge portion 19 in the present embodiment is substantially the same as that in the first embodiment, and thus the description thereof is omitted. Also, the first junction 50, which is a connection part between the optical part 66 and the first peripheral part 100, and the second junction 52, which is a connection part between the first peripheral part 100 and the second peripheral part 102, are all the first junction. Description is omitted because it is substantially the same as the embodiment.

Accordingly, as shown in FIG. 5, in the contact lens 96 of the present embodiment, the rear surface 22 of the optical part and the rear surface 106 of the first peripheral part are substantially in the shape of the surface 12 of the eyeball cornea to be worn. It is set so as to match (exactly, so as to have a substantially similar shape across the minute gap 24 that becomes the tear film), and with reference to the rear face 22 of the optical part and the rear face 106 of the first peripheral part, The rear surface 110 of the second peripheral part is gradually lifted up (separated forward) as it is directed toward the outer peripheral side, and a gap 24 with the corneal surface 12 is opened toward the outer peripheral side to facilitate tear exchange. The As shown in the figure, the corneal surface 12 is spaced apart from the cornea surface 12 toward the outer peripheral side. As is clear from this, in this embodiment, the rear surface 22 of the optical part and the rear surface 106 of the first peripheral part are both the rear face on the eyeball proximity side, and the rear surface 22 of the optical part and the rear surface of the first peripheral part 106 Force It is superposed on the cornea surface 12 in the eyeball so as to be superposed.

[0106] As described above, the contact lens 96 having a substantially spherical shell shape as a whole is formed of two different materials. Specifically, a circular region located in the center in the axial front view is a central portion 112 formed of a hard material. On the other hand, a region surrounding the central portion 112 and having an annular shape when viewed from the front in the axial direction is an outer peripheral portion 114 formed of a soft material. That is, the central portion 112 and the outer peripheral portion 114 have a coaxial rotating body shape centered on the lens central axis 14.

Note that the specific materials and the like of the central portion 112 and the outer peripheral portion 114 in this embodiment are substantially the same as those in the first embodiment, and thus detailed description thereof is omitted.

The central portion 112 and the outer peripheral portion 114 are partitioned by a circular boundary surface 116 that extends around the lens central axis 14 in the radial intermediate portion of the contact lens 96. The boundary surface 116, which is a joint portion of different materials, is positioned at the second peripheral portion 102. In particular, in this embodiment, the boundary surface 116 is positioned at a substantially central portion in the radial direction (width direction) of the peripheral portion 98. ing.

Thus, the boundary surface 116 is exposed as a boundary line 118 on the first peripheral rear surface 106 at the rear surface of the lens. In the present embodiment, the boundary surface 116 has a cylindrical shape constituted by a curved surface that extends substantially orthogonally to the lens central axis 14.

[0110] It should be noted that the external dimensions of the contact lens 96 as a general design standard value of the contact lens 96 in this embodiment: DIA, the external dimensions of the optical unit front surface 20: FOZD, the external diameters of the optical unit rear surface 22 BOZD, optical part rear 22 curvature radius: BC, first peripheral front 104 width: FP1W, first peripheral rear 106 width: BP1W, boundary 116 diameter: MDIA, MDIAZDIA The description is omitted because it is substantially the same as the first embodiment. FIG. 5 shows a contact lens according to the present embodiment in which a small-diameter contact lens whose DIA is set to 9. Omm≤DIA≤11 Omm is shown in FIG. Shown as an example.

[0111] Here, in the present embodiment, the circumferential concave groove 120 is formed so as to straddle the boundary line 118, which is the rear surface side end of the boundary surface 116, and extends over the entire circumference in the circumferential direction. It is formed to open to the side. In particular, in the present embodiment, as shown in FIG. 5, the circumferential groove 120 is formed at a radial position including the second junction 52 that is a boundary between the first peripheral rear surface 106 and the second peripheral rear surface 110. Is formed.

Thereby, on the rear surface of the contact lens 96 in the present embodiment, the corneal surface through the tear film in which the optical portion rear surface 22 and the first peripheral portion rear surface 106 have a substantially constant thickness over the entire surface. 12 and a boundary line 118 is located around the entire surface of the cornea 12 and spaced from the entire surface.

[0113] In addition, the circumferential groove 120 in the present embodiment is desired to have a width dimension: W of 0.1 mm≤W≤3.0 mm. A depth dimension of D: 0.005 mm≤D. ≤0. 15mm is desirable. In addition, it is more desirable that the width dimension: W is 0.5 mm ≤ W ≤ 2.0 mm. The depth dimension: D is more desirably 0.05 mm ≤ D ≤ 0.1 mm. Cover and width Dimensions: If W is too small, it may be difficult to smoothly connect the opening side edge of the circumferential groove 120 to the first peripheral rear surface 106 and the second peripheral rear surface 110. . On the other hand, if the width dimension W is too large, it may be difficult to secure the required diameter of the optical part 66. In addition, if the depth dimension D is too small, the boundary line 118 positioned at the radial intermediate portion of the circumferential groove 120 may touch the corneal surface 12 and cause a poor wearing feeling. On the other hand, if the depth dimension: D is too large, the thickness of the contact lens 96 becomes too thin locally, and it may not be possible to ensure adequate strength!

[0114] As shown in FIG. 5, it is desirable that the circumferential groove 120 be formed so that the boundary line 118 is located at the approximate center in the width direction of the circumferential groove 120. However, it is not necessary that the boundary line 118 is positioned at the center in the width direction. It is sufficient if the boundary line is positioned at a part of the middle of the circumferential groove 120 in the width direction.

[0115] Further, the circumferential groove 120 is not necessarily formed so as to straddle the second junction 52, and is formed so as to straddle the boundary line 118 between the central portion 112 and the outer peripheral portion 114! The peripheral portion 68 can be formed at an arbitrary radial position on the rear surface. Incidentally, the manufacturing method of the contact lens 96 according to the present embodiment is not particularly limited, but it can also be realized by adopting the method shown in the first embodiment. In addition, since it overlaps with the description in said 1st embodiment about the manufacturing method which is strong, description is abbreviate | omitted.

[0117] In the contact lens 96 having the structure according to the present embodiment as described above, the boundary line 118, which is the rear side end of the boundary surface 116, is separated from the surface 12 of the cornea by the circumferential concave groove 120. As a result, excellent effects similar to the effects shown in the first embodiment such as the effect of improving the feeling of wearing by avoiding the contact of the boundary line 118 with the surface 12 of the cornea can be obtained. .

[0118] In particular, the circumferential groove 120, the second peripheral rear surface 110, and the edge 19 are separated from the corneal surface 12, whereas the second peripheral peripheral rear surface 110 is wider and has an area. The optical portion rear surface 22 and the first peripheral portion rear surface 106 having such a structure according to this embodiment are overlapped along the surface 12 of the cornea almost entirely. Therefore, it is superimposed on the corneal surface 12 in a relatively wide range, and is stably positioned and fixed on the corneal surface 12, and can exhibit excellent optical characteristics effectively.

[0119] Fig. 5 shows an example in which the present invention is applied to a small-diameter contact lens 96 having a diameter of about 9mm to 11mm. For example, as shown in Fig. 6, the diameter is about 11mm to 15mm. The present invention can also be applied to the large-diameter contact lens 122 of the same degree. Since each part or member of the contact lens 122 shown in FIG. 6 is substantially the same as the contact lens 96 shown in FIG. 5, the description thereof is omitted here.

[0120] Next, FIG. 7 shows a contact lens 124 as a fourth embodiment of the present invention. In the following description, members and portions that are substantially the same as those in any of the first to third embodiments are denoted by the same reference numerals in the drawings, and description thereof is omitted.

That is, the contact lens 124 according to the present embodiment as a whole has substantially the same structure as the contact lens 10 according to the first embodiment. Further, the second peripheral portion 28 is formed with a circumferential groove 126 that opens to the rear surface 38 side and extends over the entire circumference in the circumferential direction. Preferably, the circumferential groove 126 has a width dimension: W of 0.1 mm≤W≤2.Omm. More preferably, 0.5 mm ≤ W ≤ 1.5 mm, more preferably 0.8 mm ≤ W ≤ 1.2 mm.

twenty two

Has been. The depth dimension of the circumferential groove 126: D is 0.002 mm ≤ D ≤ 0.12 mm.

twenty two

More preferably, it is preferably 0.005 mm ≤ D ≤ 0. lmm, more preferably 0

2

007mm≤D ≤0.09mm.

2

[0122] In the contact lens 124 having the structure according to the present embodiment as described above, it is possible to obtain substantially the same effect as the effect described in the first embodiment.

[0123] In particular, in the contact lens 124 according to the present embodiment, a curved shape substantially similar to the corneal surface 12 is interposed via the tear film, and the second circumference is superimposed close to the corneal surface 12. The circumferential groove 126 is formed on the side rear surface 38, so that the second peripheral rear surface 38 has a radius of curvature substantially equal to the corneal surface 12 and is superimposed on the corneal surface 12 via a tear film. The area power of the part to be obtained becomes small. Therefore, the surface tension acting between the second peripheral rear surface 38 and the corneal surface 12 is reduced, and the tear liquid outside the contact lens 124 is transferred between the second peripheral rear surface 38 and the corneal surface 12 facing surface. Thus, it is easily supplied to the tear film located on the cornea covered by the contact lens 124, and oxygen supply to the cornea by tear exchange can be advantageously realized.

[0124] The force described above for some embodiments of the present invention is merely an example, and the present invention should be construed in a limited manner by the specific description in the strong embodiment. is not.

[0125] For example, in the first to fourth embodiments, at least a part of the rear surfaces of the peripheral portions 18, 68, 98 is curved so as to follow the surface 12 of the cornea. , 6 8, 98 A part of the rear surface of the corneal surface 12 does not need to be superposed so as to be substantially similar to the shape. Specifically, for example, the rear surface of the optical part is formed with a radius of curvature substantially the same as the surface of the cornea, and is superimposed via the tear film, and the cornea as the rear surface of the peripheral part goes to the outer peripheral side. Surface force may be formed so as to be gradually separated.

[0126] Further, as shown in the first to fourth embodiments, the central portions 56, 88, 112 are formed of a gas permeable hard material, and the outer peripheral portions 58, 90, It is desirable that 114 is formed of a water-containing soft material in terms of oxygen supply to the cornea, but is not necessarily limited to such a configuration and material. Specifically, for example, the central part May be formed of a hard material that does not have gas permeability, or the outer peripheral portion may be formed of a non-hydrous soft material.

[0127] Furthermore, in the first to fourth embodiments, the contact lenses 10, 64, 96 (122) having the central portions 56, 8 8, 112 and the outer peripheral portions 58, 90, 114, which are made of different materials. ), 1 24 The multi-material contact lens according to the present invention is not necessarily composed of only two members using different materials, and the central portion and the outer peripheral portion are made of two or more different materials. Depending on the shape of the contact lens, it is possible to realize a contact lens constituted by joining a plurality of three or more members using different materials as a whole. In this case, not only the joint portion of the central portion and the outer peripheral portion, but also the joint portions of the members having different materials are the same as the boundary lines shown in the first to fourth embodiments. In addition, it is desirable to be able to be separated from the surface 12 of the cornea.

[0128] In the first to fourth embodiments, the outer peripheral portions (second peripheral portion 102, third peripheral portions 28, 78) of the peripheral portions 18, 68, 98 are gradually increased toward the outer peripheral side. It is separated from the surface 12. In addition, the oxygen supply to the cornea by the tear fluid exchange can be advantageously realized by setting the peripheral portion to such a structure, but such a structure is not necessarily required.

[0129] In addition to the spherical shape, the curved shape of the front surfaces 20, 70 of the optical part is an aspherical shape taking account of aberrations, a toric surface, a bifocal (bifocal) surface composed of two curved surfaces, multiple Various shapes such as a multifocal (multifocal) surface constituted by a curved surface can be appropriately employed depending on the required assistance or correction of the optical characteristics of the eye. Further, as the rear surfaces 22 and 72 of the optical unit, various shapes such as an aspherical surface and a toric surface in addition to the spherical surface can be appropriately employed depending on the shape of the eyeball surface 12 and the like.

[0130] Further, as shown in the first to fourth embodiments, the rear surfaces of the peripheral portions 18, 68, 98 do not necessarily need to be configured by a single curved surface. Further, the rear surface of the peripheral portion may be configured by combining the flat surfaces. Further, any of the plurality of surfaces may be a curved surface having a shape substantially similar to the corneal surface 12 and may be superimposed on the corneal surface 12. Specifically, for example, the outer peripheral rear surface has a diameter The curved surface located on the outermost periphery of the plurality of bay curved surfaces is formed in a shape along the corneal surface and is superimposed on the corneal surface. Also good. One or more curved surfaces of the plurality of curved surfaces may be formed in a curved shape that protrudes toward the rear surface side.

In addition, although not listed one by one, the present invention can be carried out in a mode that incorporates various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the invention.

Claims

The scope of the claims

[1] For a multi-material contact lens that has a central part made of hard lens material and an outer peripheral part made of soft lens material,

An optical part having predetermined optical characteristics is formed in the central part, and the boundary between the central part and the outer peripheral part is positioned with respect to the peripheral part formed on the outer peripheral side of the optical part,

A boundary line between the central portion and the outer peripheral portion of the rear surface of the lens as compared with the rear surface of the rear side of the optical portion and the rear surface of the peripheral portion, which is closer to the eyeball surface. The curvature radius of the rear surface of the lens in the region where the boundary is located is made different from the curvature radius of the rear surface near the eyeball so that the separation distance between the eyeball surface and the eyeball surface is larger. contact lens.

[2] In the rear surface of the rear surface of the optical part and the rear surface of the peripheral part, which is formed with a radius of curvature closer to the curvature of the eyeball surface and having a smaller radius of separation from the surface of the eyeball. The various distances in the curvature radius direction of the boundary line between the central portion and the outer peripheral portion on the rear surface of the lens with respect to the extension line: X is 0.01 mm ≤ x ≤ 0.25 mm. Material contact lens.

[3] The lens rear surface of the peripheral portion is configured by a plurality of bay curved surface regions having different curvature radii in the radial direction, and is different from the region outside the inner peripheral side peripheral portion where the boundary line is located. The multi-material contact lens according to claim 1, wherein a peripheral portion on the outer peripheral side having a curvature is formed.

[4] The rear surface of the optical part is closer to the radius of curvature of the eyeball surface than the rear surface of the peripheral part on the outer peripheral side, and is formed with a radius of curvature so that the separation distance from the eyeball surface is smaller. 4. The multi-material contact lens according to claim 3, wherein the rear surface of the inner peripheral side peripheral portion is formed so as to smoothly connect the rear surface of the optical portion and the rear surface of the outer peripheral side peripheral portion in the radial direction.

[5] The rear surface of the outer peripheral side peripheral portion is closer to the radius of curvature of the eyeball surface than the rear surface of the optical unit, and is formed with a radius of curvature so that the separation distance from the eyeball surface is smaller. , Smoothly connecting the rear surface of the outer peripheral side peripheral portion and the rear surface of the optical portion in the radial direction 4. The multi-material contact lens according to claim 3, wherein a rear surface of the inner peripheral side peripheral portion is formed as described above.

[6] The rear surface of the optical part, the rear surface of the inner peripheral side peripheral part, and the rear surface of the outer peripheral side peripheral part are all formed by a concave curved surface, and the inner peripheral side is more than the rear surface of the optical part. The rear surface of the side peripheral portion has a larger radius of curvature, and the rear surface of the outer peripheral side peripheral portion has a larger radius of curvature than the rear surface of the inner peripheral side peripheral portion. The multi-material contact lens according to any one of 5.

[7] A groove is formed in the rear surface of the lens where the boundary line is located, and a groove is formed in the rear surface of the lens so as to extend over the entire circumference. The boundary line is positioned on the inner surface of the groove. The multi-material contact lens according to claim 1 or 2.

[8] Width dimension of the groove: W force 0.1 mm≤W≤3. Omm and depth dimension of the groove: D is 0.005 mm≤D≤0.15 mm Item 8. The multi-material contact lens described in Item 7.

[9] The Young lens modulus of the hard lens material forming the central portion is 3 MPa to 3000 MPa, and the Young modulus of the soft lens material forming the outer peripheral portion is 0.2 MPa to 3 MPa. The multi-material contact lens according to any one of 1 to 8

10. The central portion is formed of an oxygen permeable hard lens material.

The multi-material contact lens according to any one of 9.

[11] The multi-material contact lens according to any one of claims 1 to 10, wherein the outer peripheral portion is formed of a hydrous soft lens material.

12. A peripheral groove that is open to the rear surface side of the lens and extends continuously over the entire circumference in the circumferential direction is formed in a portion on the outer peripheral side of the boundary line of the peripheral portion. The multi-material contact lens according to any one of the above.