JPH06230320A - Soft contact lens superior in wearing feeling - Google Patents

Abstract

PURPOSE:To obtain the soft contact lens which is hardly fixed to the cornea and superior in wearing feeling by providing a position where tear liquid is collected inside the bevel of the rear surface of the contact lens and outside its optical visual field part. CONSTITUTION:This soft contact lens has at least one place (tear liquid collection part 2) where the tear liquid is collected inside the bevel of the contact lens. A conventional lens is easy to become dry, and consequently the lens has a little movement or sometimes does not move, so that the lens is easily fixed to the cornea. The tear liquid collection place 2 inside the bevel may be formed by any method, but the tear liquid collection place 2 is formed generally by forming the rear surface curve of so called 'intermediate curve area' between the bevel part and optical visual field part of the contact lens into a multicurve in >=2 stages including a radius of curvature larger than the radius of curvature of a base curve and a smaller radius of curvature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft contact lens having a lens design excellent in wearability. More specifically, the present invention relates to a soft contact lens which does not adhere to the cornea during wearing and has excellent lens movement and which is comfortable to wear.

[0002]

2. Description of the Related Art Soft contact lenses include water-containing soft contact lenses and non-water-containing soft contact lenses, and water-containing soft contact lenses are often used because of their excellent wearing comfort. Further, as a non-hydrated soft contact lens, for example, JP-A-54-813 is used.
63, JP-A-58-127914 and JP-A-48-75047.

However, although the non-hydrous soft contact lens is post-treated so that the material thereof is hydrophobic and the surface thereof is hydrophilic, it still has a problem that sticking to the cornea is likely to occur, and it has not been widely used in general. . on the other hand,
The water-containing soft contact lens also has a problem that when the indoor humidity is low, the lens is dried and the movement of the lens is reduced, so that the lens easily sticks to the cornea.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a soft contact lens that is less likely to stick to the cornea and is excellent in wearability.

[0005]

In order to solve the above problems, the present inventors have studied the material characteristics and lens design of soft contact lenses, and as a result of intensive studies, as a result, a specific lens suitable for the material characteristics has been obtained. It was found that the purpose can be achieved by making the structure, and the present invention was completed.

That is, the present invention is as follows. 1. A soft contact lens having at least one portion where tears are stored inside the bevel on the rear surface of the contact lens and outside the optical visual field. 2. 2. The soft contact lens according to 1 above, wherein the portion where the tear fluid is stored is annular and is formed by forming the back curve with a multi-curve having two or more steps. 3. The soft contact lens according to the above 1, wherein the part where the tear fluid is stored has a concave structure. 4. 3. The soft contact lens according to 1, 2, or 3 above, which comprises a polymer having a water content of 5% or less and an elastic modulus of 10 × 10 ⁷ dyn / cm ² or less. 5. The polymer is a silicon-based polymer whose main component is a macromer having a polymerizable unsaturated group at the molecular end of a polyalkylsiloxane, a polyfluoroalkylsiloxane or a hydroxyl-containing poly (fluoro) alkylsiloxane. The soft contact lens according to 4 above.

The present invention will be described in detail below. The soft contact lens of the present invention is a soft contact lens having a structure having at least one site where tears are stored (hereinafter referred to as a tear storage site) inside the bevel of the contact lens. A lens without a tear storage area inside the bevel of a contact lens, that is, with a conventional lens design, it is easy to dry, so that the movement of the lens tends to be small, sometimes the movement is lost, and sticking to the cornea is likely to occur. .

The tear storage part inside the bevel may be formed by any method, but in general, the back curve of the so-called intermediate curve region between the bevel part of the contact lens and the optical field part is used as a base. This is achieved by forming a multi-curve with two or more steps including a radius of curvature larger than the radius of curvature of the curve and a small radius of curvature. As an example, a curve 1 having a larger radius of curvature than the base curve, a curve 2 having a smaller radius of curvature than the base curve, and a curve 3 having substantially the same radius of curvature as the base curve are provided in this order from the outer circumference of the optical field, or the base. A tear storage part is formed by constructing the rear curve of the intermediate curve region in the order of the curve 1 having a larger radius of curvature than the curve and the curve 2 having substantially the same radius of curvature as the base curve. Further, if necessary, intermediate curves may be provided at the connecting portions of these multi-curves in order to make the connecting portions between the curves smooth.

The annular tear storage portion formed by the multi-curve is outside the optical visual field (usually about 7 mm in diameter) of the contact lens and is beveled at the lens edge part (usually from the lens edge about 12 to 15 mm in diameter). 0.25-0.8
It is formed in the inner area (up to mm). Generally, when one tear storage area is provided, the lens diameter is about 8 to 1
It is preferable to provide it at a position of 0 mm because it fits well to the shape of the cornea, the movement of the lens is good, and it is stable, and the width of the tear storage part is in the range of about 0.5 to 1.5 mm. In addition, the depth is the lift amount of the lens edge (usually 0.15
mm or less), and the lens thickness at the maximum depth is equal to or greater than the lens center thickness. When the number of tear storage sites is two or more, they are provided concentrically within the above lens range. The shape of the tear storage part is not particularly limited, and may be a circle or an ellipse, and may be a spherical surface or an aspherical surface.

The lens design having the annular tear storage portion is, for example, a lens size of 13.0 mm, a bevel width of about 0.45 mm, a tear storage portion width of about 0.65 mm, and an inner diameter of the tear storage portion of 9.00 mm lens. Edge lift amount about 0.1
0 mm, the maximum depth of the tear storage part is about 0.05 mm. This lens has a good lens movement, and there is no attraction or sticking.

As another example of the tear storage portion, a soft surface having at least one portion in which a concave portion is formed inside the bevel at the peripheral portion of the rear surface of the contact lens and outside the optical visual field portion and in which the tear fluid is stored is provided. I have contact lenses. The concave portion is formed outside the optical field of view of the rear surface of a normal lens and inside the bevel portion by processing with a cutting jig and a polishing jig having a curvature smaller than the base curve of the lens. The shape and size are not particularly limited, but a horseshoe shape, a crescent shape, an eyebrow shape, a circle shape in which a part of the annular tear storage part is interrupted,
Alternatively, it may be oval. Generally, about 0.5-1.5
It has a circle, eyebrow shape, or elliptical shape having a diameter or width of mm and a depth of about ⅔ or less of the thickness of the lens. The number may be any number as long as it is 1 or more, and is usually formed point-symmetrically or line-symmetrically with respect to the center of the lens.

Any polymer suitable for soft lenses can be used in the soft contact lens of the present invention. For example, there are water-containing polymers having a water content of about 90 to 25%, or elastomers such as silicone polymers and acrylic polymers. Of these, the water content is 5% or less,
Non-hydrated porosity with a sex ratio of 10 × 10 ⁷ dyn / cm ² or less
The limmer has no protein adsorption inside the lens, which is found in water-containing soft lenses, and the lens is easy to care for, and the softness of the lens is close to that of a water-containing soft contact lens, giving it a comfortable wearing feeling. It is preferable because it does not stick to.

A polymer having a water content of 1% or less and an elastic modulus of 2 × 10 ⁷ dyn / cm ² or less is more preferable because it gives a good feel to the wearer. Any of the above polymers may be used, and examples thereof include acrylic ester elastomers, methacrylic ester elastomers, silicone elastomers, fluorosilicone elastomers, perfluoroether elastomers, polyphosphazene elastomers, and copolymers thereof. . Due to its good balance of physical properties such as oxygen permeability, stain resistance, and mechanical strength, polyunsaturated unsaturated at the molecular end of polyalkylsiloxane, polyfluoroalkylsiloxane or hydroxyl-containing poly (fluoro) alkylsiloxane. A silicon-based polymer containing a macromer having a group as a main component is preferable. Specific examples of these macromers and polymers are described in, for example, JP-A-3-240021.
JP-A-3-257420, JP-A-4-50814
Japanese Patent Application, Japanese Patent Application No. 3-202106, Japanese Patent Application No. 3-333
No. 026 and the like. Typical examples thereof include macromers represented by the following chemical formulas 1 to 8 which are homopolymerized or copolymerized with a monomer copolymerizable therewith.

[0014]

[Chemical 1]

[0015]

[Chemical 2]

[0016]

[Chemical 3]

[0017]

[Chemical 4]

[0018]

[Chemical 5]

[0019]

[Chemical 6]

[0020]

[Chemical 7]

[0021]

[Chemical 8]

The contact lens of the present invention can be manufactured by a conventional lens manufacturing method, for example, a method of cutting from a polymer block with a lathe and polishing, a monomer composition in a polymerization mold corresponding to the shape of the lens. There is a casting method of injecting and polymerizing, or a method of casting and polymerizing only one surface of a lens with a polymerization mold and finishing the other surface by a cutting and polishing method. When the tear storage part of the present invention is formed by a cutting and polishing method, the part is cut and polished into a predetermined shape,
When it is formed by a cast polymerization method, it is manufactured by forming a shape corresponding to a lens on a predetermined portion of the mold by a cutting and polishing method.

[0023]

EXAMPLES The present invention will be described in detail below with reference to examples.

[0024]

Example 1 50 parts by weight of a siloxane macromer represented by the following chemical formula 9, 20 parts by weight of trifluoroethyl methacrylate, 15 parts by weight of n-butyl acrylate, 1,3-bis (3-methacryloxypropyl) -1, 1, 3, 3-
5 parts by weight of tetradimethylsiloxane and 0.5 parts by weight of benzyl dimethyl ketal were dissolved and mixed under a nitrogen atmosphere. This mixture was mixed with a diameter of 13.00 mm, a base curve of 8.40 mm, a bevel curve of 12.00 mm, a bevel width of 0.45 mm, an inner diameter of a tear storage part of 9.00 mm, and a width of 0.
65 mm (2 with radius of curvature 9.00 mm and 8.5 mm
A contact lens having a step curve), a lens power of −3.00, a center thickness of 0.12 mm, and a lens edge thickness of 0.10 is poured into a polypropylene mold capable of mold polymerization, and irradiated with ultraviolet rays at 45 ° C. for 15 minutes. I got a transparent lens.

[0025]

[Chemical 9]

The obtained lens was precisely weighed and then kept at 37 ° C.
The water content determined by dipping in purified water for 72 hours and then precisely weighing
0.3%, tensile elastic modulus is 2.0 × 10⁷dyn /
cm ²Met. Also, the base curve of the obtained lens
Add fluorescein reagent (2% aqueous solution) to the side and bend
Bebebe installed on the base curve prototype with a radius of 8.40
Between the lens part and the lens diameter range of 9.0 mm to 9.65 mm
Fluorescein liquid is stored in a ring at two locations.
Is confirmed, and even if the lens is moved up and down, its annular part
Liquid is stable and the movement of the lens is smooth.
It was

[0027]

Example 2 55 parts by weight of a siloxane macromer represented by the following Chemical formula 10 and 25 of trifluoroethyl methacrylate
By weight, 20 parts by weight of n-butyl acrylate, 6 parts by weight of methacrylic acid, 4 parts by weight of ethylene glycol dimethacrylate and 0.5 parts by weight of benzyl dimethyl ketal were dissolved and mixed under a nitrogen atmosphere.

This mixture was mixed with a diameter of 13.00 mm, a base curve of 8.40 mm, a bevel curve of 12.50 mm,
Bevel width 0.45 mm, inner diameter of tear storage part 9.00 m
m, width 0.65 mm (composed of a two-step curve with a curvature radius of 10.40 mm and 9.0 mm), lens power-3.
00, center thickness 0.10 mm, lens edge thickness 0.1
A contact lens of No. 0 was poured into a polypropylene mold capable of mold polymerization and was irradiated with ultraviolet rays at 45 ° C. for 15 minutes to obtain a transparent lens.

[0029]

[Chemical 10]

The obtained lens was precisely weighed and then immersed in purified water at 37 ° C. for 72 hours and then weighed precisely to find a water content of 0.35% and a tensile elastic modulus of 1.9 × 10 ⁷ dyn.
Was / cm ² . Further, fluorescein reagent (2% aqueous solution) was dropped on the base curve side of the obtained lens,
It was confirmed that fluorescein solution was annularly stored in two places, a bevel part and a lens diameter range of 9.0 mm to 9.65 mm, when it was attached to a base curve prototype with a radius of curvature of 8.40. Even if the lens was moved up and down, the annular liquid part was stable and the movement of the lens was smooth.

[0031]

Comparative Example 1 The same monomer mixture as used in Example 2 was prepared, with a diameter of 13.00 mm and a base curve of 8.40 m.
m, bevel curve 12.50mm, bevel width 0.45m
m, lens power-3.00, center thickness 0.10 mm,
A contact lens having a lens edge thickness of 0.10 was poured into a polypropylene mold capable of mold polymerization and irradiated with ultraviolet rays at 45 ° C for 15 minutes to obtain a transparent lens.

The obtained lens was precisely weighed, immersed in purified water at 37 ° C. for 72 hours, and then precisely weighed to find a water content of 0.35% and a tensile elastic modulus of 1.9 × 10 ⁷ dyn.
Was / cm ² . Further, fluorescein reagent (2% aqueous solution) was dropped on the base curve side of the obtained lens,
When mounted on a prototype base curve with a radius of curvature of 8.40, it was confirmed that the fluorescein solution was annularly stored only in the bevel part, and as soon as the lens was moved up and down, the bevel curve part had less liquid. The lens edge part turned up, and the lens became difficult to move, and the lens stuck to the prototype.

[0033]

EFFECTS OF THE INVENTION The soft contact lens of the present invention has a stable tear movement between the posterior surface of the contact lens and the cornea so that the movement of the lens is smooth and stable, and the lens does not adhere to the cornea. It has excellent wearability.

[Brief description of drawings]

FIG. 1 is a schematic view showing a tear storage part showing an example of a soft contact lens of the present invention.

FIG. 2 is a schematic diagram showing another example of the soft contact lens of the present invention showing a tear storage part.

[Explanation of symbols]

 1 Tear reservoir of bevel curve 2 Tear reservoir of the present invention

Claims (5)

[Claims] 1. A soft contact lens having at least one site where tears are stored inside the bevel on the rear surface of the contact lens and outside the optical visual field. 2. The soft contact lens according to claim 1, wherein the portion where the tear fluid is stored is annular and is formed by forming the back curve by a multi-curve having two or more steps. . 3. The soft contact lens according to claim 1, wherein the portion where the tear fluid is stored is formed by a concave surface portion. 4. The soft contact lens according to claim 1, 2 or 3, wherein the contact lens is made of a polymer having a water content of 5% or less and an elastic modulus of 10 × 10 ⁷ dyn / cm ² or less. 5. The polymer is polyalkyl siloxane,
The silicone-based polymer containing a macromer having a polymerizable unsaturated group at the molecular end of a polyfluoroalkylsiloxane or a poly (fluoro) alkylsiloxane having a hydroxyl group as a main component, as a main component. Soft contact lens.