JPH0511541B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for processing soft ophthalmic lens materials. More specifically, the present invention is applicable to the field of ophthalmological medical products and other products that require precision machining, and in particular to machining materials that are essentially or partially made of soft materials under strict standards. The present invention relates to a method for processing soft ophthalmic lens materials that can be suitably used in the field of ophthalmic lenses such as contact lenses and intraocular lenses. [Prior Art] Among various materials that exist as ophthalmic lens materials, hydrous soft ophthalmic lens materials mainly made of poly2-hydroxyethyl metal acrylate or polyN-vinylpyrrolidone absorb water and swell. It has been in the spotlight in recent years because it has the property of softening and is comfortable to wear, and it easily conforms to the cornea. However, when a material that softens with water is used, for example, as a soft contact lens, it has the following drawbacks. (b) Because it is water-containing, excreta from lachrymal fluid can easily accumulate inside the material, often causing serious damage to the eyes. (b) Bacteria can easily breed on the lenses, making it a hassle to pay special attention to how to use and store them, including periodic sterilization by boiling. Therefore, in order to eliminate the drawbacks of soft contact lenses mentioned above and not impair the feeling of wearing, soft eye lens materials that do not contain water or have only a slight water content have been developed for use in soft contact lenses and other ophthalmic lenses. Application to lens materials has been proposed. In general, materials that soften with water have a relatively high glass transition temperature in the unabsorbed state;
Since it is hard enough to be cut, it is often cut into a desired shape in an unabsorbed state, and then softened with water to obtain ophthalmic lenses such as contact lenses. On the other hand, soft ophthalmic lens materials that do not contain water or only slightly contain water have a low glass transition temperature and are flexible at room temperature, making it difficult to perform cutting treatments.
Or it was impossible. As methods for manufacturing ophthalmic lenses such as contact lenses using such soft ophthalmic lens materials, the following two methods have been proposed. (1) A processing method in which soft ophthalmic lens material is cooled and hardened, and then cut
13583 and Special Publication No. 57-53569). (2) A method in which a monomer that provides a soft material is injected into a mold and polymerized to produce a molded product, or an oligomer such as a urethane precursor, silicone precursor, or liquid rubber is injected into a mold and cured. Mold forming methods, such as methods for producing molded products. The cutting method (1) above requires large-scale equipment to cool the soft material, which increases the cost and makes it uneconomical.Also, the soft material itself becomes brittle when cooled, making cutting difficult. There is a problem that can occur. In addition, in the molding method (2), when a molded article is produced by injecting a monomer into a mold and polymerizing it to produce a molded article, shrinkage occurs during polymerization, causing distortion and polymerization. It is difficult to obtain a molded product with the desired shape because it is prone to unevenness, mass production requires a large number of molds of various specifications, and when volatile monomers are used, There is a problem in that a part of the monomer evaporates during polymerization, making it impossible to obtain a molded article with a desired shape. When producing a molded article by injecting an oligomer into a mold and curing it, volumetric shrinkage occurs during curing, making it difficult to obtain a molded article with the desired shape. This is difficult and the resulting molded product may have unevenness, burrs, etc., making it difficult to apply to fields that require precision processing, such as contact lenses, and furthermore, it is difficult to mass-produce. Since it requires a large number of molds of various standards,
There are problems such as it being uneconomical. Furthermore, when producing molded products by extrusion molding or calendering raw rubber and then vulcanization molding, mass production requires a large number of molds of various specifications, and It is difficult to perform precision processing such as cutting on molded products. [Problems to be Solved by the Invention] Therefore, the present inventor has made efforts to easily manufacture molded products having a desired shape from soft ophthalmic lens materials that can solve the problems of the conventional technology as described above. As a result of repeated research, we have discovered a method for processing soft ophthalmic lens materials that can solve these problems, and have completed the present invention. [Means for Solving the Problems] That is, the present invention is characterized in that the hard polymer is removed from a molded article obtained by cutting a polymer blend consisting of a soft material and a hard polymer into a desired shape. The present invention relates to a method for processing soft ophthalmic lens materials. [Function] Normally, soft ophthalmic lens materials are difficult to cut at room temperature, but according to the method for processing soft ophthalmic lens materials of the present invention, a hard polymer is used in addition to conventional soft materials. Therefore, it can be easily cut into a desired shape at room temperature without cooling, and if the hard polymer contained in the molded product material is removed after cutting, it can be used as a conventional soft ophthalmic product. A molded article made of a soft ophthalmic lens material having properties comparable to those of the lens material can be obtained. [Example] As the soft material used in the present invention, a material having a crosslinked structure due to chemical bonds or ionic bonds and having the property that these bonds do not disintegrate by the solvent, monomer, etc. used in the present invention is used. However, the soft materials used here are those that are difficult or impossible to use mechanical processing methods such as cutting under normal environments and atmospheres in a state that is not swollen with water or other solvents. refers to what is possible. When the glass transition temperature of a soft material exceeds 40°C, it becomes rigid under normal environments and atmospheres without being swollen with water or other solvents, making it possible to use mechanical processing methods such as cutting. So,
A temperature of 40°C or lower, particularly 30°C or lower, is preferably applicable to the present invention. Specific examples of monomers that provide the soft material include methyl acrylate, ethyl acrylate,
Isopropyl acrylate, n-propyl (meth)acrylate, isobutyl acrylate, n
-Butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tetradecyl (meth)acrylate, lauryl (meth)acrylate, ) acrylate, cyclohexyl (meth)acrylate, 2-ethoxyethyl acrylate, 3
- Alkyl (meth)acrylates such as ethoxypropyl acrylate, 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, alkoxyalkyl (meth)acrylates, organosiloxysilylalkyl (meth)acrylates, fluoroalkyl (meth)acrylates, etc. Acrylic esters; 4-dodecylstyrene, 4
-hexylstyrene, 4-nonylstyrene, 4-
Styrenes such as alkylstyrenes such as octylstyrene, organosiloxysil(alkyl)styrenes, and fluoroalkylstyrenes; vinyl esters such as vinyl acetate and cyclopentyl acetate; dienes such as chloroprene, isoprene, and butadiene; ethyl vinyl ether, Examples include monomers that provide soft materials such as vinyl ethers such as butyl vinyl ether, but these monomers may be used alone or in combination of two or more. The monomers providing these soft materials may be copolymerized with other monomers. Examples of the other monomers mentioned above include 2-hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate, and
acrylate, hydroxyalkyl (meth)acrylates such as hydroxypropyl (meth)acrylate, 2-dimethylaminoethyl (meth)
Acrylate, 2-butylaminoethyl (meth)
(alkyl)aminoalkyl (meth)acrylates, (meth)acrylamides, such as acrylates,
Glycerol (meth)acrylate, propylene glycol mono(meth)acrylate, polyglycol mono(meth)acrylate, vinylpyrrolidone, (meth)acrylic acid, maleic anhydride, maleic acid, aminostyrene, hydroxystyrene, etc., but also oxygen permeable In the case of imparting a ) Acrylates, etc. In addition, if other functions are to be added in addition to these, glycidyl (meth)acrylate,
Glycidyl allyl ether, vinyl chloroacetate,
Examples include 2-chloroethyl vinyl ether. The other monomers are added in an amount of 0.1 to 100 mol parts, particularly 10 to 50 mol parts, per 100 mol parts of the monomers providing the soft material. In addition, when adjusting the hardness of a soft material, for example, methyl methacrylate, t-butyl methacrylate, styrene, t-butylstyrene, α-methylstyrene, (meth)acrylonitrile, vinyltoluene, etc. are used as monomers that provide the soft material.
0.1 to 100 mole parts per 100 mole parts, especially
10 to 100 mole parts are added. These other monomers may be used alone or in combination of two or more of the monomers that provide the soft material, if necessary. Note that a crosslinking agent is added to the monomers that provide these soft materials, or a mixture of these and other monomers, if necessary, for crosslinking. As the crosslinking agent, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate,
1,4-butylene glycol dimethacrylate,
1,3-butylene glycol dimethacrylate,
Aryl diglycol carbonate, triaryl cyanurate, diaryl phthalate, N,
Examples include N'-methylenebisacrylamide, N,N'-methylenebismethacrylamide, and divinylbenzene. The crosslinking agent is usually a monomer that provides a soft material or a mixture of these and other monomers.
0.1 to 10 mole parts per 100 mole parts, especially
It is used by adding 0.5 to 4 mole parts. Examples of soft materials include polyethylene, polyisobutylene, natural rubber, emulsion polymerization styrene/butadiene rubber, solution polymerization styrene/butadiene rubber, fluorine rubber, etc., in addition to the monomers that provide the above-mentioned soft materials or soft materials made of these and other monomers. A polymer crosslinked with a suitable crosslinking agent or a suitable crosslinking method can be used in the present invention. Suitable crosslinking methods include, for example, sulfur,
Examples include methods of crosslinking using organic peroxides, radiation, and the like. For example, a copolymer composed of n-butyl acrylate and 2-chloroethyl vinyl ether can be crosslinked with sulfur, and such a crosslinked product can also be used in the present invention. Furthermore, in addition to the above, silicone rubber or polyurethane obtained by an addition reaction between vinyl-terminated polydimethylsiloxane and polymethylhydrosiloxane may also be used. The hard polymer used in the present invention is a linear polymer that does not contain or form a crosslinked structure, and whose glass transition temperature is at least 60°C.
℃, preferably 90℃ or above, a polymer can be used which provides a degree of hardness to impart sufficient machinability to the polymer blend at room temperature and under normal environmental conditions; Specific examples include polymethyl methacrylate, poly t-
Butyl methacrylate, polystyrene, poly α-
Methylstyrene, polyt-butylstyrene, polyvinyl chloride, poly4-methylpentene-1, polymethacrylic acid and its salts, polyacrylamide, poly(meth)acrylonitrile, poly2-chlorostyrene, poly3-chlorostyrene, etc. Examples include condensation polymers such as vinyl polymers, polyesters, polyamides, polycarbonates, polyphenylene oxides, polyacetals, and polycellulose acetates. These polymers may be used alone or in combination of two or more. It's okay. A polymer blend is obtained by mixing the soft material and the hard polymer, for example, by impregnating the soft material with a monomer that provides the hard polymer and polymerizing the soft material. The soft material and the hard polymer may be mixed to such an extent that the obtained polymer blend can be cut at room temperature and in a normal environmental atmosphere,
Therefore, it is sufficient that the soft material and the hard polymer are dispersed to such an extent that a polymer blend having the desired hardness can be obtained, but it is preferable that the soft material and the hard polymer be uniformly dispersed. The proportion of the soft material and hard polymer in the polymer blend cannot be determined unconditionally because it depends on the hardness of the intended lens material, but the proportion of the soft material and the hard polymer in the polymer blend cannot be determined unconditionally, but the proportion of the soft material and the hard polymer in the polymer blend varies from 20 to 60% (by weight, the same applies hereinafter). ), the hard polymer is preferably added in a range of 80-40%. The polymer blends are obtained by impregnating a soft material with monomers that give a hard polymer and then polymerizing the monomers. First, a method for producing a polymer blend will be explained. When the polymer blend is produced by impregnating a soft material with a monomer that provides a hard polymer and then polymerizing the monomer, the soft material must be three-dimensionally insolubilized with a crosslinking agent or the like, Furthermore, although this crosslinking is done by chemical bonds or ionic bonds, it is necessary that these bonds are not destroyed during the series of steps. Among the monomers that have the ability to swell soft materials, monomers that form a linear polymer that does not contain a crosslinked structure after polymerization are selected as monomers that provide the above-mentioned hard polymer. are methyl methacrylate, t-butyl methacrylate, styrene, t-
Examples include butylstyrene and (meth)acrylonitrile. In addition, when using an acrylic soft material made of polyalkyl acrylate as the soft material, for example, methyl methacrylate, t-butyl methacrylate, etc. are preferably used as monomers that provide the hard polymer.
The present invention is not limited to these, and other materials may also be used. Examples of methods for impregnating a hard material with a monomer that provides a hard polymer and then polymerizing the monomer include radical polymerization, ionic polymerization, photopolymerization, ultraviolet polymerization, radiation polymerization, and polyaddition. In particular, when radical polymerization is applied, polymerization is possible at room temperature and pressure, and the polymerizable species is not easily affected by impurities in the polymerization system and can be reproduced without requiring much effort for purification. It is preferable because it has good properties. However, when monomers are polymerized by radical polymerization, if a side reaction such as chain transfer of polymerization initiator radicals or growing radicals to a soft material occurs, a chemical reaction between the hard polymer and the soft material may occur. When the hard polymer is extracted later using a solvent, the hard polymer cannot be completely extracted and remains, making it difficult to obtain an ophthalmic lens with the desired shape or elasticity. There are some things I can't do. In order to suppress the occurrence of such side reactions, polymerization reaction initiators, monomers, and soft materials may be appropriately selected and used to prevent side reactions from occurring. In order to prevent chain transfer, it is preferable to mix a chain transfer agent or a compound that is susceptible to chain transfer into the monomers before polymerization. Examples of the chain transfer agent or compound that is susceptible to chain transfer include mercaptans such as n-butylmercaptan, dodecylmercaptan, and thioglycolic acid, disulfides such as tetraalkylthiuram disulfide and xanthate disulfide, diazothioether, and 2-propanol. , chloroform, bromoform, carbon tetrachloride,
Examples include carbon tetrabromide, acetaldehyde, butyraldehyde, etc., but these compounds are preferably mixed by being dissolved or emulsified in the monomer that provides the hard polymer. The chain transfer agent is used per 100 mole parts of the monomer that gives the hard polymer.
In the present invention, it is preferable to use it in an amount not exceeding 10 mol parts. The polymerization initiator used in polymerizing the monomer to provide the hard polymer includes azobisisobutyronitrile, 2,2'-
azobis(2,4-dimethylvaleronitrile),
Azo initiators such as 2,2'-azobis(4-methoxy2,4-dimethylvaleronitrile), organic peroxides such as benzoyl peroxide and di-t-butyl peroxide, potassium persulfate, ammonium persulfate, etc. Usually, 0.01 to 0.5 mole part is used per 100 mole parts of the monomer. Further, during polymerization, an appropriate amount of inert solvents may be mixed in for the purpose of controlling the degree of swelling of the soft material.
Such inert solvents include benzene, toluene, dimethyl oxide, etc., and these inert solvents are used in an amount not exceeding 30 parts by weight per 100 parts by weight of the monomer that provides the hard polymer. is preferable. Note that it is preferable to select and use soft materials and hard polymers that exhibit compatibility, but if they are used in combination with materials that do not exhibit good compatibility, a compatibilizer may be added to improve the compatibility. It is preferable to dissolve or emulsify and mix in the monomer providing the hard polymer. Examples of compatibilizers that can be used in the present invention include those having one component that is a soft material or a polymeric component that has good compatibility with it, and one component that has a hard polymer or a polymeric component that has good compatibility with it. Examples include block or graft polymers. These compatibilizers are usually added in an amount of 1 to 10 parts by weight per 100 parts by weight of the polymer blend. For example, when a silicone soft material is cured with styrene, the compatibility is poor and it is not possible to obtain a preferred polymer blend. Alternatively, it is preferable to mix a graft copolymer of poly(styrene-g-dimethylsiloxane) or the like. After polymerization and curing as described above, the resulting polymer blend is cut in a normal environment and atmosphere, and if necessary, polished to obtain a molded product of the polymer blend. A molded product of a polymer blend contains a hard polymer in a soft material, and is cured in a swollen state, so it may shrink slightly when the hard polymer is removed, which will be described in detail later. Therefore, it is preferable to determine the swelling degree of the molded article in advance and cut the molded article into the desired size and shape according to the determined swelling degree. Next, the cut molded article is immersed in a suitable solvent to remove the hard polymer contained in the soft material. The suitable solvent is one that has the ability to dissolve hard polymers and swell soft materials. Specific examples of such solvents include chloroform, methylene chloride, ethylene chloride, carbon tetrachloride, benzene, toluene, xylene, tetrahydrofuran, dioxane, methyl ethyl ketone, ethyl acetate, and methyl acetate. In addition to solvents, other solvents can also be used. Next, after sufficiently removing the hard polymer from the molded product, the molded product is dried to form an ophthalmic lens having a desired shape. Next, the method for processing a soft ophthalmic lens material of the present invention will be explained based on Examples, but the present invention is not limited to these Examples. Example 1 98.1 parts of n-butyl acrylate (parts by weight, the same applies hereinafter), 1.8 parts of ethylene glycol dimethacrylate
After degassing a mixture consisting of 0.1 part, 2,2' part and 0.1 part of azobis(2,4-dimethylvaleronitrile), it was poured into a cylindrical glass container with an inner diameter of 12 mm, and nitrogen gas was sent into the glass container. Then, a stopper was placed on the opening of the glass container, and the temperature was increased to 30°C for 48 hours, then the temperature was gradually increased to 50°C for 5 hours, and 80°C for 3 hours.
Polymerization was performed at 100°C for 2 hours to obtain a soft material. The obtained soft material was highly elastic and transparent at room temperature. Next, 10 parts of the resulting cylindrical soft material cut into short pieces were uniformly mixed with 97.6 parts of methyl methacrylate, 2 parts of dodecyl mercaptan, and 0.4 parts of 2,2'-azobis(2,4-dimethylvaleronitrile). The solution was poured into a cylindrical glass container with an inner diameter of approximately 16 mm, and the container was immersed in the solution.The container was then filled with nitrogen gas, the container was capped, and the soft material was heated to a temperature slightly lower than 30°C. After reaching a swollen state, polymerization was carried out at 30° C. for 3 days to obtain a polymer blend. The resulting polymer blend was slightly cloudy. Next, the obtained polymer blend was cut into a contact lens shape at room temperature and in a normal environmental atmosphere and polished. Since the polymer blend was hard, cutting and polishing were easy. The resulting molded product was immersed in chloroform for 5 hours to swell, the hard polymer component polymethyl methacrylate was removed, and when dried, the surface was sufficiently polished and had the same elasticity as the soft material that was the raw material. A molded article having the shape of a transparent contact lens was obtained. Comparative Example 1 A soft material was prepared in the same manner as in Example 1, and an attempt was made to perform cutting, but such cutting could not be performed. Example 2 78.6 parts of n-butyl acrylate, 19.6 parts of n-butyl methacrylate, 1.7 parts of ethylene glycol dimethacrylate and 2,2'-azobis(2,
After deaerating a mixture consisting of 0.1 part of 4-dimethylvaleronitrile, it was poured into a cylindrical glass container with an inner diameter of 12 mm, nitrogen gas was introduced into the glass container, and a stopper was then placed in the opening of the glass container. set, 30
℃ for 48 hours, then gradually increase the temperature to 50℃ for 5 hours,
Polymerization was carried out at 80°C for 3 hours and at 100°C for 2 hours to obtain a soft material. The obtained soft material was highly elastic and transparent at room temperature. Next, the obtained soft material was immersed in the same solution as used in Example 1 to obtain a polymer blend in the same manner as in Example 1. The resulting polymer blend was slightly cloudy. The resulting polymer blend was then cut into the shape of a contact lens at room temperature in a normal environment and polished. Since the polymer blend was hard, it was easy to cut or polish. The resulting molded product was immersed in chloroform for 5 hours to swell, the hard polymer component polymethyl methacrylate was removed, and when dried, the surface was sufficiently polished and had the same elasticity as the soft material that was the raw material. A molded article having the shape of a transparent contact lens was obtained. Comparative Example 2 A soft material was prepared in the same manner as in Example 2, and an attempt was made to perform cutting, but such cutting could not be performed. Example 3 A mixture consisting of 98.1 parts of ethyl acrylate, 1.8 parts of ethylene glycol dimethacrylate, and 0.1 part of 2,2'-azobis(2,4-dimethylvaleronitrile) was degassed and then placed in a cylindrical glass container with an inner diameter of 12 mm. Nitrogen gas was introduced into the glass container, and then a stopper was placed at the opening of the glass container, and the temperature was raised to 30°C for 48 hours, and then gradually heated to 50°C for 5 hours.
Polymerization was carried out at 80°C for 3 hours and at 100°C for 2 hours to obtain a soft material. The obtained soft material was highly elastic and transparent at room temperature. Next, 10 parts of the soft material obtained, 97.6 parts of methyl methacrylate, 2.1 parts of dodecyl mercaptan,
A cylindrical glass container with an inner diameter of approximately 16 mm is filled with a solution containing 0.3 part of 2,2'-azobis(2,4-dimethylvaleronitrile), and the container is immersed in the solution, and nitrogen gas is filled into the container. Close the stopper 30
The soft material was allowed to reach an equilibrium swelling state at a temperature slightly below 0.degree. C. and then polymerized at 30.degree. C. for 3 days to obtain a polymer blend. The resulting polymer blend was transparent. Next, the obtained polymer blend was cut into a contact lens shape at room temperature and in a normal environmental atmosphere and polished. Since the polymer blend was hard, cutting and polishing were easy. The resulting molded product was immersed in chloroform for 5 hours to swell, the hard polymer component polymethyl methacrylate was removed, and when dried, the surface was sufficiently polished and had the same elasticity as the soft material that was the raw material. A molded article having the shape of a transparent contact lens was obtained. Comparative Example 3 A soft material was prepared in the same manner as in Example 3, and an attempt was made to perform cutting, but such cutting could not be performed. Examples 4 to 9 A mixture of raw materials for a soft material having the composition shown in Table 1 was polymerized in the same manner as in Example 1 to obtain a soft material. The obtained soft material was highly elastic, soft, and transparent at room temperature. Next, 10 parts of the obtained soft material were placed in a container filled with a uniformly mixed solution of 97.6 parts of methyl methacrylate, 2 parts of dodecyl mercaptan, and 0.4 parts of 2,2'-azobis(2,4-dimethylvaleronitrile). It was then immersed in the solution, and then polymerized in the same manner as in Example 1 to obtain a polymer blend. The resulting polymer blend was slightly cloudy. Next, the obtained polymer blend was cut into the shape of a contact lens at room temperature in a normal environmental atmosphere and polished. Since the polymer blend was hard, cutting and polishing were easy. The obtained molded product was immersed in chloroform in the same manner as in Example 1, and then dried, the surface was sufficiently polished and it had the shape of a transparent contact lens with the same elasticity as the soft material that was the raw material. A molded product was obtained.

[Table] Example 10 10 parts of ADAPT-60L (manufactured by Kokusai Chemical Co., Ltd.), a directly connected 12 mm cylindrical urethane rubber that is transparent, soft and highly elastic at room temperature, and 97.6 parts of methyl methacrylate,
A polymer blend was obtained by treating in the same manner as in Example 1, except that it was immersed in a mixed solution consisting of 2 parts of dodecyl mercaptan and 0.4 parts of 2,2'-azobis(2,4-dimethylvaleronitrile). The resulting polymer blend was transparent. Next, the resulting polymer blend was cut into the shape of a contact lens and polished. Since this polymer blend was hard, it was easy to cut and polish. Next, the hard polymer contained in the molded product was removed in the same manner as in Example 1, and when it was dried, the surface was sufficiently polished and a transparent contact with the same elasticity as the soft material that was the raw material was obtained. A molded article having a lens shape was obtained. Comparative Example 4 Urethane rubber ADAPT-60L used in Example 10
I tried to cut it, but it was not possible to do so. [Effects of the Invention] As explained above, according to the processing method of the present invention, cutting of soft materials, which is normally impossible, can be easily and accurately produced without requiring a large amount of equipment or cost. In addition, when producing very small molded products, it is possible to process them in a swollen state with high precision. Also, for example, when cutting plastics such as polymethyl methacrylate, which is commonly known as a raw material for hard contact lenses in the contact lens field, the inherent brittleness of plastics may cause the material to chip or crack during processing. However, the blend obtained by the processing method of the present invention also has the properties of a plastic reinforced with a soft material, so it has excellent impact resistance and does not have the brittleness characteristic of plastics. It is also possible to eliminate it. Therefore, no chips or cracks occur during cutting. Furthermore, according to the processing method of the present invention, it is also possible to easily process a composite contact lens, which is known in the field of contact lenses and has a hard center area and a soft peripheral area.

Claims (1)

[Claims] 1. Processing of a soft ophthalmic lens material, characterized by removing the hard polymer from a molded product obtained by cutting a polymer blend consisting of a soft material and a hard polymer into a desired shape. Method. 2. The method of processing a soft ophthalmic lens material according to claim 1, wherein the polymer blend is obtained by impregnating a soft material with a monomer that provides a hard polymer and then polymerizing the monomer.