CA1279142C - Uv-absorbing extended-wear lenses - Google Patents

Abstract

UV-ABSORBING EXTENDED-WEAR LENSES

Abstract of the Disclosure There are provided extended-wear lenses formed by polymerizing an organosilicon monomer, a fluoroorgano monomer, a hydrophilic monomer, and a crosslinking agent.
The product includes a benzotriazole and/or a benzophenone UV-absorbing agent and is is easily machinable to any prescription, permitting continuous wear, with high oxygen permeability and a receding contact angle of less than 45°C. The bulk of the monomer content is the fluoorgano monomer and/or organosilicon monomer, which content is limited to 40 parts by weight, with lesser amounts being preferred.

Description

~L2~9~2 C27~:16751:JPG:477 -1-UV-ABSORBING EXTENDED-WEAR LENSES

Background of the Invention The present invention is Airected to ~ye-compatible lenses, particularly hard contact lenses having excellent oxygen permeability and wettahility.
Contact lenses presently on the market are classi-fied into two large ~roups: soft contact lenses and h~rd contact lenses. Hard contact lenses ~re better able than soft contact lenses to retain visual ~haracteristics, but are less comfortable. The art has sought to increase oxygen per~eability of hard contact lenses, to extend the length o time they can ~e worn without causing corneal damage or discomort.
One propos~d solution has 6een the formation of a copolymer of methyl methacrylat~ and a siloxane methacry-3 late compound. This solution has been less than satis-factory, since the ~enses offere~ are not as hard, rigid, nor wetta~le as lenses formed from polymethyl methacryl-ate. In addition, such lenses are fragile and have poor mechanical processability.

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~ ..

~127~4Z

1 The object of the present invention is to overcome the deficiencies in the state of the art by offering lenses having a high degree of oxygen permeability, excellent wettability, and, if desired, ultraviolet absorption. The primary benefit of UV absorptivity is the resistance to user development of cataracts.

Summary of the Invention The present invention is directed to oxygen-permeable UV-absorhing lenses comprising copolymers of ~t least one organosilicon monomer which is preferably an organosilane or an organosiloxane of the general formula:

CH2 = C-Rl OH
l l Coo-(cH2-cH-cH2o)a-lcH2)b-x (1) wherein Rl is hydrogen or methyl, a is 0 or 1, b is from 1 to about 4, an~ X is an organosilicon moiety containing up to about 16 silicon atoms;

CH2 = C - Ml I (2) COO--~M)a--~CH2)c~Y

wherein Ml i.s hydrogen, alkyl, fluoroalkyl, alkyl car-boxy, carboxy ester, alkyl carboxy ester, fluorinated carboxy ester, fluorinat~d alkyl carboxy ester, cyano, or phenyl, M is hydroxy alkyl, alkyl ether, or hydroxy alkyl ether, a is as defined above, c is from 0 to 4, an~ Y is a fluorocarbon group, preferably containing from about 2 to about 21 fluorine atoms.

14i~

1 At least one hydrophilic monomer is included, preferably an unsaturated carboxylic acid capable of inducing wettability, and is present in an amount suffi-cient to provide in the resultant polymer a receding contact angle of about 45 or less. Methacrylic acid is preferred. At least one UV-absorbing agent is included.
The UV-absorbing agent may be a UV-absorbing monomer, preferably hydroxybenzophenone or a benzotriazole compound of the formula:

( CH2 = I-R
Coo-(cH2-cHoH-cH2o)a- (C~2)b ~ Z (3 ~ d wherein Rl, a and b are as defined above, d is 1 or 2, and Z is:

OH O OH

20 ~2 ~ C ~ o _ ;
DH

~ ~ ~ ; or ~N~

wherein R2 is hydrogen, alkyl or hydroxy. Alternately or in addition. the UV-absor~ing monomer may be a ben~o-triazole of the formula:
OH

3 ~ N ~ 2 C~-- CH2 3S ~1 ~L27~ 4Z

l wherein Rl and R2 are as defined above, and R3 is H or alkyl, preferably a Cl-Clo alkyl, provided to induce UV absorbance to the lens.
The UV-absorbing agentlmay also be non-polymerizable homopolymers and copolymers, preferably containing UV-absorbing units which are added to the monomer system that undergoes polymerization and which become physically entrained in the formed lens.
In the polymerized state, the UV-absorbing monomers act as a UV filter or screen capable ~f preventing UV
transmission to the eye. It is important that in this regard most of the complications associated with cornea aphakia and retina problems can be prevented. In addi-tion, the phenolic moiety enhances wettability of the lens. Moreover, being compatible with the other monomers, the UV-absorbing monomers are readily copolymerized and permanently retained in the polymer chain. Migration to the polymer surface and leaching are avoided.
A final component is a crosslinking monomer which is a crosslinking agent. preferably a silicon monomer, present in an amount up to about 5, preferably up to about 2, percent by weight.
lt has been found that the total organosilicon-monomer content of the polymer may range from about 10 to ahout 40 percent by weight, preferably from about 10 to about 35 percent by weight, more preferahly 30 percent by weight. The hydrophilic monomer may be present in an amount of from ~hout 1 to ahout 15 percent by weight, preferably from ahout 2 to about 10 percent by weight.
The UV agent may be present in an amount of from ahout 0.1 to about 2n percent, preferably from about 2 to ahout 10 percent by weight, and the crosslinking monomer may be present in an amount up to about 2 percent by weight.
All percentages are hased on the total weight of the UV-absorhing agent and the monnmers. The balance of the 1~914~

1 monomer system may be solely the fluoroorgano monomers.
It is desired that the lens have a Shore D hardness greater than about 78, preferably from about 80 to about 85. There may be desirably included other monomers such as acrylates, methacrylates, itaconic esters, styrenes, fluorinated styrenes, alkyl styrenes, fluorinated alkyl styrenes, and the like, present in a concentration of up to about 50 percent by weight of the concentration of the fluoroorgano monomer, typically in a concentration of up to about 5 percent by weight based on the total weight of the UV-absorbing agent and the monomers. Such monomers are used to modify properties such as hardness, machina bility, wettability, oxygen permeability, and the like.
It is desired to provide an oxygen permeability at 15 35C greater than 50 x 10 11(cm2/sec.)~ml O2/ml x mm Hg).
When using low-cost fluoroorgano compounds such as 2,2,2-trifluoroethylmethacrylate, the organosilicon content of the monomer system must be high, typically in ; the range of from 25 percent to 30 percent or more by weight based on the total weight of the UV-absorbing agent and the monomers. Organosilicon monomer content can be advantageously reduced, however, by inclusion of high-performance fluoroorganomonomers such as hexafluoro-isopropylmethacrylate.

1~7~4Z

Detailed Descri~tion The present invention is directed to eye-compatible, i.e., ocular-compatible, lenses, in particular, hard contact lenses, formed of an interpolymeriz~d amount of at least one organosilicon monomer, at least one fluoro-organo compound, at least one monomeric unsaturated carboxylic-acid wetting agent, and a UV-absorbing agent which is preferably a monomer of benzotriazole and/or henzophenone, and at least one crosslinking monomer.
Other reactive monomers such as acrylates, methacrylates, itaconic esters, styrenes, fluorinated styrenes, alkyl styrenes, fluorinated alkyl styrenes, and the like, may be included as part of the polymerizable composition, to achieve a lens of desired hardness, wettability, oxygen permeahility, machinability, and the like.
The organosilicon monomers which may be used in accordance with the instant invention include organo-silanes and/or organosiloxanes of the general formula:

CH2 = IC-Rl Coo-(cH2-cHoH-cH2o)a-~cH2)b-~ (1) wherein Rl is hydrogen or methyl, a is 0 or 1, b is from 1 to about 4, and X is an organosilicon moiety containing up to about 26 silicon atoms.
Preferred organosilicon compounds are acrylates and methacrylates of the general formula:

CH,2 = IC-Rl C~o(-cH2-cHoH-cH2-o-)a~~cH2)~-x (2) 79~L4Z

16751 -7_ R4 l6 lR6 wherein X' is -7i-(CH2)b-fi-R7 or fi 7 each of R4 and Rs is independently a Cl-Cs alkyl, phenyl, or -O-Si(CH3)3, and each of R6, R7 and R8 is independently selected from Cl-Cs alkyl; -CH2=CH2; phenyl; -CH2OH;

-o-Si-O-Si(CH3)3 ; -O-f i-OH

/ O-Si(CH3)3 -O-SiCH3 ; o-si- [osi ( CH3)3]3 ; or o-si ( CH3)3 CH2 = C-Rl I

Coo-(cH2-cHoH-cH2-o-)a~~cH2)b- ' wherein Rl, a, and b are as defined above.
The representative monomers included are:
tris(trimethylsiloxy)silylpropylmethacrylate, 1,3-bis(~-methacryloxypropyl)-1,1,3,3-tetra(trimethyl-siloxy)disiloxane, vinyl di(trimethylsiloxy)silylpropylmethacrylate, 3 pentamethyldisiloxy-~-methacryloxypropylsilane, trimethylsilylpropylmethacrylate, methyl di(trimethylsiloxy)silylpropylmethacrylate, and tris(trimethylsiloxy)silylpropylglycerolmethacrylate, and the like. Tris(trimethylsiloxy)-~-methacryloxypropyl-: 35 1~79~2 16751 -~B-1 silane is presently preferred. Another important monomer is 1,3-bis~ methacryloxypropyl)-1,1,3,3-tetra(trimethyl-siloxy)disiloxane, as it ~er~es as a ceosslinking ~gent without ~acrificing oxygen permeability. ~hen u~ed for this purpose, concentration ~ay vary from about 0.1 to about 2 parts by weisht based on the total weight of the reactants.
Other useful organosilicon monomers are disclosed in U.S. Patents 4,1~2,508 to Ellis; 4,153,641 to Deichert et al; 4,189,546 to Deichert et al: and 4,463,149 to Ellis.

While concentrations of organo~ilicon monomers may range from ahout 10 to abvut 40 parts by weight based on the total weight of the UV-absorbing agent ~nd the mono-mers, the preferred range is from about 10 to about 35, more preferably from about 20 t~ about 30 parts by weight.
Oxygen permeability (all other factors being constant) will increase with an increase in organosilicon monomer content. At higher levels, the lens becomes more diffi-cult to machine, reguiring the inclusion of ~onomers as part of the monomer system, as mentioned above, to yield a lens having a Shore D hardness greater than about 78,~
preferably from about 80 to about 85.
The fluoroorgano monomers utile in the practice of the instant invention are generally compounds of the formula:

CH2 = C - Ml I (3) COO-(M)a-(C~2)c~y wherein Ml is hydrogen, alkyl, fluoroalkyl, alkyl car-boxy, carh~xy ester, alkyl carboxy ester, fluorinated carhoxy ester, fluorinated alkyl carboxy es~er, cyano, or phenyl, M is hydroxy alkyl, alkyl ether, or hydroxy alkyl ~ ,.

~279~42 l6751 -9-l ether, a is as defined above, c is from O to 4, and Y is a fluorocarbon group, preferably containing from about 2 to about 21 fluorine atoms. Preferably, Y has the formula:
CnF2n+l lDr CnF2nW-Illustrative of fluoroorgano monomers are:
2,2,2-trifluoroethylmethacrylate, hexafluorobutylmethacrylate, hexafluoroisopropylmethacrylate, pentafluoro-n-propylmethacrylate, and the like.
Trifluoroisopropylmethacrylate is the preferred monomer for oxygen permeability, with 2,2,2-trifluoroethyl-methacrylate being preferred for cost. Perfluoro or fluorinated styrenes may also be used.
Hydrophilic monomers are include~ in the composition to induce wettability. They preferably comprise an unsaturated carhoxylic acid, most preferably methacrylic acid, for compatability of monomers and wearer comfort.
Acrylic acid is functional but less desirable. Other monomers such as 2-hydroxyethylmethacrylate and the like may be used. Concentration may be from ahout 0.1 to about 15 or more percent by weight, preferably from about 2 to about lO percent hy weight based on the total weight of the UV-absorbing agent and the monomers.
The amount of hydrophilic monomer present depends on the amount of UV-ahsorbing agent, as described below, is employed, as the latter also has the capahility of being a hydrophilic agent. Whether in monomeric or in poly-meric form, its concentration may range from ahout 0.1 toabout 20 percent hy weight, preferably from about 2 to about 10 percent hy weight based on the total weight of the monomers. The ~V absorhing agents used herein are preferably in a polymerized form and cooperate with the ~2~ 4%

1 hydrophilic monomer to induce wettability and antiseptic-ability, i.~., self-sterilizable, in consequence of hydroxy-substituted benzene moieties. In the polymerized state, the UV absorbers absorb in the range of from about 30nnm to ahout 450nm, preferably with no less than about 70% UV radiation at 370nm. Preferred UV-absorbing agents are, or are formed of, monomers of the formula:

~H2 = C-Rl Coo-(cH2-cHoH-cH2-o-)a~(cH2-)b ~ Z (4) ~ d wherein Rl is hydrogen or methyl, a is 0 or 1, b is from about 1 to about 4, d is l or 2, and Z is:
OH O OH
R2 ~ C ~ o _ ;
ON
C ~ ~ N~ D--wherein R2 is hydrogen; an alkyl, preferably a Cl-Cs alkyl or hydroxyl, and c is 1 or 2. In the alternative or in addition, there may be employed a phenyl benzotriazole of the formula:

R3~N~ ~ R2 C\- CH2 n lZ7~4~

1 wherein Rl and R2 are as defined above, preferably a Cl-Clo alkyl, and R3 is H, alkyl, preferably a Cl-Clo alkyl, or hydroxyl.
Preferred ~V absorbers include:
2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-acryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and the like.
The UV-absorbing agents are either part of the mono-mer system or are high-molecular-weight, non-polymerizable homopolymers or copolymers preferably containing such monomers as described above or other ~V-absorbing units.
They are reacted as such with the polymerizable monomer system and are entrained in the polymerization product.
The hard contact lenses of the instant invention are formulated to have high oxygen permeability (Dk) of at least about 15 and preferably greater than 50, as expressed in units of 10 11(cm2/sec.)(ml O2/ml x mm Hg) ; 20 and as determined at 35C. Values are achieved using high concentrations of the organosilicon monomer and/or selection of the fluoroorgano monomer. With compositions of high organosilicon-monomer content there are displayed increased brittleness and a reduction in capability to undergo machining. At least one crosslinking agent, such as a multi-functional organosilicon monomer, a fluoro-organo monomer, or other modifying monomer, is employed in an amount sufficient to control hardness of the lens in the range of Shore D hardness of from about 80 to about 85. A highly multi-functional organosilicon monomer is preferred, as it does not interfere with oxygen permea-bility. Other crosslinking agents which may be used include ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, and the like.

~27~142 1 Lens formation is by free radical polymerization such as azobisisobutyronitrile (AIBN) and peroxide catalysts under conditions set forth in U.S. Patent 3,808,179. Colorants and the like may be added prior to monomer polymerization.
It is preferred to form the lens base in sheet form between layers of a non-adherent surface. The sheet is cut into smaller lense precursors from which the lens is ground to user specifications. Spin-casting, as described for instance in U.S. Patent 3,408,429, may also be used.

Without limiting, the following Examples are illus-trative of the instant invention~ Wi~h referencs to the Examples, properties of the contact lenses were measured according to the following methods.
Oky~en permeability values were determined using a test method developed by Dr. Irving Fatt of Berkeley, California, and disclosed in the paper, entitled: "Oxygen Transmissibility ~nd Permeability of Gas Permeable Hard Contact Lenses and Materials" by Irving Fatt, Ph.D., International Contact Lens Clinic, Vol. 11, No. 3, March -1984. The instrument was ~ polarographic cell with a curved surface for finished lenses, polarographic amplifier, recorder and a constant temperature chamber equipped wit~ a temparature control unit. The measurements were made at 35C and the units of oxygen permeability (Dk) are (cm2/sec.)(ml 02/ml x mm Hg).
The water wettability of the contact lense material was determined by the sesile drop method using a Rame-Hart goniometer with an environmental chamber. Both the advancing and the receding contact angles were determined.
m e hardness was measured as Shore D at 22C using a hardness tester, and percent light transmission was measured using a recording spectrophotometerO
The absorption spectra of the copolymer were determined on a "Perkin Elmer" UV-Vis spectrophctometer using 0.1-0.15mm-thin optically polished discs. The 16751 -13- ~
1 amount of materials extractable from the lenses were ; evaluated by first storing them in a saline solution for 10 days at 35C. The lenses were then rinsed with distilled water, dried, weighed, and placed in stoppered, 5 25cc volumetric flasks, again containing saline as the extracting medium. The saline was analyzed daily for its extracted ultraviolet absorber by placing 4cc of the extract in a spectrophotometer cell and determining the absorption at 320nm. The absorption values were compared against the calibration curve made for the pure ultravio-let absorber. Extractables can also be determined by the Soxhlet extraction method, using water as the solvent~
The amount of extractables was determined only for a few of the materials in the Examples. Based on 0.04gr average lens weight, extractables'were found, on the average, to be less than 1 x 10~4mc grams/lens/day.
For a few selected copolymer materials, the leacha-bility-diffusibility was evaluated by cytotoxicity assay-agar overlay method.
The assay is based on the method described by Guess, W.L., Rosenbluth, S.A., Schmidt, B., and Autian, J., in nAgar Diffusion Method for Toxicity Screening of Plastics on Cultured Cell Monolayers", J. Pharm. Sci. 54:1545-1547, 1965, and is designed '-to detect the response of a mammalian monolayer cell culture to readily diffusible components from materials or test solutions applied to the surface of an agar layer overlaying the monolayer.
The r~sponse of the cell monolayer is evaluated, with respect to the discoloration of the red-stained mono-layer, under and aro~nd the sample when the petri dish isviewed against a white background. Loss of color of the stained cells is considered to be a physiologically sig-nificant reaction of the cells. The extent of discolora-tion is confirmed by examination of the monolayer on aninverted microscope, and the extent of lysis of the cells within the discoloration zone is estimated. Typically, ~.~279~D~Z

1 discoloration of cells precedes lysis, as manifested by a region and a region showing lysis. A sample is reported as "cytotoxic" only if lysis is observed.

_xample 1 An oxygen-permea~le copolymer was prepared from a mixture of 25 parts by weight of tris(trimethylsiloxy-)-~-methacryloxypropylsilane, 65 parts by weight of trifluoroethylmethacrylate, 5 parts by weight of 2-hydroxy-4-(2-acryloxyethoxy)benzophenone, 5 parts by weight of methacrylic acid, and 0.02 parts by weight of AIBN.
The mixture was homogenized, degassed and placed in a polymerization cell made of two glass plates separated by a seal and held together hy spring clamps. After filling, the cell was purged with nitrogen, sealed and placed in a circulating water bath at 6noc for 10 hours.
After the initial polymerization period, the cell was heated at ~0C for 3 hours, 100C for one hour, and then Z allowed to cool to room temperature. The clamps were then removed and the transparent sheet heated for 2 hours at 100C. The plastic sheet, about 14-inch in thickness, was cut into squares, then formed to discs which were used to prepare corneal contact lenses using conventional hard-contact-lens-making equipment. The properties of this lens material are shown in Table I.

TA~LE I
_ _ 3 Properties Example 1 Oxygen Permea~ility 54 Contact Angle 20 Light Transmission Trans~arent Hardness 84 3S Cytotoxicity Assay Negative ~2~42 l6751 -15-Examples 2-22 and Control A
Following the procedure of Example 1, additional polymers were formed for lens use. The composition, in parts-by-weight of reactants and lens properties, are shown in Table II. The Control does not include a hy~rophilic monomer nor a UV-absorbing monomer.

1~79~42 o m ~r r ~ v ~' N Itl C Ir~ N ~1 1~

o ¦ o~--~ o Ul C ~ ~ Z

o~ I o Irl ou) o 11~ I Z

01 ~-- U~ O h'7 ~ N 0 l o N .t:
, _ ¦ 2 ~ ~ ~ ~ N 0 ~ V ~ O 1~ 0 u~ ' N
15 ~ o u~

l N¦u~ o u~ o 0 _ _ E~ ~ z ~ ? ~ ~ D

~IL2,'7~L42 G O ~ r) 0 ~ I c~ I` ~ o 1~1 ~ o P ~r ~ ¦ ~ E o N N X

~ ¦ N .D 0 ~ O U~ P~ r ~ ~
ol¦ o E u~ ~ o ,n ~ ~ ~ ~c 10~ s --I N ~ q o ~r~ N N

~ ~ _ ~
-- ~¦ ~ ~ o u~ o ~1` ~ 0 ~ z ~¦ ¦ u, u~ o u~ N _ ~D

1~ N U~ U 0 I` E'~ N

20 ~I N --¦ ~ ~ n N
ID

~ j;.d.
~b~
3 ~ L N ~ ~ N ~ N ~ Z

~27~L42 Example 23 Following the procedure of Examples 1-14, lenses were made from a polymer formed by polymerizing 24 parts by weight tris(trimethylsiloxy)silylpropylmethacrylate, 1 part by weight 1,3 bis~-methacryloxypropyl)-1,1,3,3 -tetra(trimethylsiloxy)disiloxane, 5 parts by weight methacrylic acid, 5 parts by weight 2-hydroxy-4-(2-acryl-oxyethoxy)benzophenone, and 65 parts by weight 2,2,2 -trifluoroethylmethacrylate. The lenses formed were transparent, with an oxygen permeability of 54 x 10-11 (cm2/sec.)(ml 02/ml x mm Hg) and a receding contact angle of about 20~C.
Two evaluations were made. In one, over 300 persons wore fitted lenses during normal waking hours. Another group wore the lenses 24 hours per day. Both groups wore the lenses for protracted periods of time without discomfort. In another study, patients unable to wear soft lenses, or any other commercial oxygen-permeable lens, were able to wear the lenses with complete comfort.
Clinical reports from participating doctors suggest that the lenses performed better and were safer than any other lens used, and also suggest a potential for years of trouble-free wear. Patients confirmed excellent wetta-bility, no forming of film or deposit, and no sensitivity to glare. These results were unexpected, because silicon compounds do not wet well and are not durable.

Example 24 Following the procedure of Examples 1-14, an oxygen-permeable copolymer was prepared from a mixture of 22 parts by weight tris(trimethylsiloxy)-~-methacryloxy-propylsilane, 2.7 parts by weight hydroxy-di(trimethyl-siloxy)sily:Lpropylmethacrylate, 0.3 parts by weight 1,3 bis(~-methacryloxypropyl)-1,1,3,3-tetra(trimethyl-~:7~142 I siloxy)disiloxane, 65 parts by weight trifluoroethyl-methacrylate, 5 parts by weight 2-hydroxy-4-(2-acryloxy-ethoxy)henzophenone, ~ parts by weight methacrylic acid, and 0.02 parts by weight AIBN. The properties of this lens material are shown in Table III.

TA~LE III

Oxygen Permeability 54 Contact Angle 20 Light Transmission Transparent Hardness 84 : 15 Cytotoxicity Assay Negative

Claims (30)

1. An oxygen-permeable UV-absorbing lens comprising at least one UV-absorbing agent, the total amount of W -absorbing agent present being in an amount of from about 0.1 to about 20 percent by weight of a polymer comprised of:
a) an organosilicon monomer system present in an amount of from about 10 to about 40 percent by weight based on the total weight of the UV-absorbing agent and the monomers;
b) at least one hydrophilic monomer present in an amount sufficient to provide in the resultant polymer a contact angle of less than about 45°;
c) at least one crosslinking monomer, the total of crosslinking monomer being present in an amount up to about 5 percent by weight based on the total weight of the monomers; and d) the balance of the monomers comprising at least one fluoroorgano monomer of the formula:
wherein M1 is hydrogen, alkyl, fluoroalkyl, alkyl carboxy, carboxy ester, alkyl carboxy ester, fluorinated carboxy ester, cyano, or phenyl, M is hydroxy alkyl, alkyl ether, or hydroxy alkyl ether, a is as defined above, c is from 0 to 4, and Y is a fluorocarbon group.

2. An oxygen-permeable UV-absorbing lens as claimed in claim 1 in which the UV-absorbing agent is a non-reactive homopolymer or copolymer.

3. An oxygen-permeable UV-absorbing lens as claimed in claim 2 in which the UV-absorbing homopolymer or copolymer comprises an interpolymerized amount of at least one UV-absorbing monomer selected from the group consisting of a hydroxybenzophenone or benzotriazole of the formula:
wherein R1 is hydrogen or methyl, a is 0 or 1, b is from 1 to about 4, and Z is:
;
; or wherein R2 is hydrogen, alkyl or hydroxy and a phenyl benzotriazole of the formula:
wherein R1 and R2 are as defined above, and R3 is H;
alkyl or hydroxyl.

4. An oxygen-permeable lens comprising an interpolymerized amount of:
a) an organosilicon monomer system including monomers of the formula:
wherein R1 is hydrogen or methyl, a is 0 or 1, b is from 1 to about 4, and X is an organosilicon moiety containing up to about 16 silicon atoms, the total organosilicon monomer being present in an amount of from about 10 to about 35 percent by weight based on the total weight of the monomers;
b) at least one UV-absorbing monomer selected from the group consisting of a hydroxybenzophenone or benzotriazole of the formula:

wherein R1 is hydrogen or alkyl, a is 0 or 1, b is from 1 to about 4, and Z is:

wherein R2 is hydrogen, alkyl or hydroxy and a phenyl benzotriazole of the formula:
;
; or wherein R1 and R2 are as defined above, and R3 is H;
alkyl or hydroxyl, said UV-absorbing monomer being present in an interpolymerized amount of from about 0.1 to about 20 percent by weight based on the total weight of the monomers;
c) at least one hydrophilic monomer present in an amount sufficient to provide in the resultant polymer a contact angle of less than about 45°;
d) at least one crosslinking monomer, the total of crosslinking monomer being present in an amount up to about 5 percent by weight based on the total weight of the monomers; and e) the balance of the monomers comprising at least one fluoroorgano monomer of the formula:
wherein M1 is hydrogen, alkyl, fluoroalkyl, alkyl carboxy, carboxy ester, alkyl carboxy ester, fluorinated carboxy ester, fluorinated alkyl carboxy ester, cyano, or phenyl, M is hydroxy alkyl, alkyl ether, or hydroxy alkyl ether, a is as defined above, c is from 0 to 4, and Y is a fluorocarbon group, said lens having a Shore D hardness greater than about 78.

5. An oxygen-permeable UV-absorbing lens as claimed in claim 4 in which the organosilicon monomer is present in a concentration of from about 20 to about 30 percent by weight based on the total weight of interpolymerized monomers.

6. An oxygen-permeable UV-absorbing lens as claimed in claim 1, 2 or 3, in which the lens has oxygen permeability of at least about 15 x 10-11.

7. An oxygen-permeable UV-absorbing lens as claimed in claim 1, 2 or 3, in which the oxygen permeability is at least about 50 x 10-11.

8. An oxygen-permeable UV-absorbing lens as claimed in claim 4 in which the organosilicon monomers are selected from compounds of the formula:
wherein X' is or wherein each of R4 and R5 is independently a C1-C5 alkyl, phenyl, hydroxyl, or -O-Si(CH3)3, and each of R6, R7 and R8 is independently selected from C1-C5 alkyl;
-CH2=CH2; phenyl; hydroxyl; -CH2OH;
; ;

; O-Si-[OSi(CH3)3]3 ; or wherein R1 is hydrogen or alkyl, a is 0 or 1, and b

9. An oxygen-permeable UV-absorbing lens as claimed in claim 1 in which the organosilicon monomer is selected from tris(trimethylsiloxy)-?-methacryloxypropylsilane, 1,3-bis-(?-methacryloxypropyl-)1,1,3,3-tetra(trimethyl-siloxy)disiloxane and mixtures thereof.

10. An oxygen-permeable UV-absorbing lens as claimed in claim 4 in which the organosilicon monomer is selected from tris(trimethylsiloxy)-?-methacryloxypropylsilane, 1,3-bis-(?-methacryloxypropyl-)1,1,3,3-tetra(trimethyl-siloxy)disiloxane and mixtures thereof.

11. An oxygen-permeable UV-absorbing lens as claimed in claim 1 in which the fluoorgano monomer is 2,2,2 -trifluoroethylmethacrylate, hexafluorobutylmethacrylate, hexafluoroisopropylmethacrylate and mixtures thereof.

12. An oxygen-permeable UV-absorbing lens as claimed in claim 9 in which the fluoorgano monomer is 2,2,2 -trifluoroethylmethacrylate, hexafluorobutylmethacrylate, hexafluoroisopropylmethacrylate and mixtures thereof.

13. An oxygen-permeable UV-absorbing lens as claimed in claim 4 in which the fluoorgano monomer is 2,2,2 -trifluoroethylmethacrylate, hexafluorobutylmethacrylate, hexafluoroisopropylmethacrylate and mixtures thereof.

14. An oxygen-permeable UV-absorbing lens as claimed in claim 10 in which the fluoorgano monomer is 2,2,2 -trifluoroethylmethacrylate, hexafluorobutylmethacrylate, hexafluoroisopropylmethacrylate and mixtures thereof.

15. An oxygen-permeable UV-absorbing lens as claimed in claim 1 in which the hydrophilic monomer is methacrylic acid.

16. An oxygen-permeable UV-absorbing lens as claimed in claim 5 in which the hydrophilic monomer is methacrylic acid.

17. An oxygen-permeable UV-absorbing lens as claimed in claim 14 in which the hydrophilic monomer is methacrylic acid.

18. An oxygen-permeable UV-absorbing lens as claimed in claim 1 in which the UV-absorbing agent comprises a monomer selected from the group consisting of 2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-acryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and mixtures thereof.

19. An oxygen-permeable UV-absorbing lens as claimed in claim 3 in which the UV-absorbing agent comprises a monomer selected from the group consisting of 2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-acryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and mixtures thereof.

20. An oxygen-permeablle UV-absorbing lens as claimed in claim 4 in which the UV-absorbing agent comprises a monomer selected from the group consisting of 2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-acryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and mixtures thereof.

21. An oxygen-permeable UV-absorbing lens as claimed in claim 14 in which the UV-absorbing agent comprises a monomer selected from the group consisting of 2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-acryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and mixtures thereof.

22. An oxygen-permeable lens comprising an interpolymerized amount of:
a) an organosilicon monomer system including the formula:
wherein R1 is hydrogen or methyl, a is 0 or 1, b is from 1 to about 4, and X is an organosilicon moiety containing up to ahout 16 silicon atoms, the total organosilicon monomer heing present in an amount of from about 10 to about 35 percent by weight based on the total weight of the monomers;

Claim 22, continued. . .
b) from 0 to about 10 percent by weight of the monomers of a UV-absorbing monomer selected from the group consisting of a hydroxybenzophenone or benzotriazole of the formula:
wherein R1, a and b are as defined ahove, d is 1 or 2, and Z is:
;

; or wherein R2 is hydrogen, alkyl or hydroxy and a phenyl benzotriazole of the formula:
wherein R1 and R2 are as defined above, and R3 is H;
alkyl, preferably a C1-C10 alkyl, or hydroxyl, said UV-absorbing monomer beint present in an interpolymerized amount of from ahout 2 to about 10 percent by weight based on the total weight of the monomers;

Claim 22, continued. . .
c) methacrylic acid in an amount sufficient to provide in the resultant polymer a contact angle of less than about 45°;
d) at least one crosslinking monomer, the total of crosslinking monomers being present in a concentration of from about 0.1 to about 2 percent by weight based on the total weight of the monomers; and e) the balance of the monomers comprising at least one fluoroorgano monomer of the formula:
wherein M1 is hydrogen, alkyl, fluoroalkyl, alkyl carboxy, carboxy ester, alkyl carboxy ester, fluorinated carboxy ester, cyano, or phenyl, M is hydroxy alkyl, alkyl ether, or hydroxy alkyl ether, a is as defined above, c is from 0 to 4, and Y is a fluorocarbon group preferably containing from about 2 to about 21 fluorine atoms, said lens having a Shore D
hardness greater than about 78 and an oxygen permeability of at least 15 x 10-11(cm2/sec.)(m1 O2/ml x mm Hg).

23. An oxygen-permeable UV-absorbing lens as claimed in claim 22 in which the organosilicon monomer is present in a concentration of from about 20 to about 30 percent by weight based on the total weight of interpolymerized monomers.

24. An oxygen-permeable UV-absorbing lens as claimed in claim 22 in which the organosilicon monomer is selected from the group consisting of tris(trimethylsiloxy)-methacryloxypropylsilane, 1,3-bis-(?-methacryloxypropyl)-1,1,3,3-tetra(-trimethyl-siloxy)disiloxane and mixtures thereof, and in which the hydroxyorganosilicon monomer is hydroxy-di(trimethyl-siloxy)silylpropylmethacrylate.

25. An oxygen-permeable UV-absorbing lens as claimed in claim 20 in which the fluoroorgano monomer is 2,2,2-trifluoroethylmethacrylate, hexafluorobutyl-methacrylate, hexafluoroisopropylmethacrylate and mixtures thereof.

26. An oxygen-permeable UV-absorbing lens as claimea in claim 25 in which the UV-absorbing monomer is selected from the group consisting of 2-hydroxy-4-(2-methacryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-acryloyloxyethoxy)benzophenone, 2-hydroxy-4-(2-hydroxy-3-methacryloxypropyl)benzophenone, 2-(2-hydroxy-5-vinylphenyl)-2H-benzotriazole, and mixtures thereof.

27. An oxygen-permeable UV-absorbing lens as claimed in claim 1 wherein the fluorocarbon group is from about 2 to about 31 fluorine atoms.

28. An oxygen-permeable UV-absorbing lens as claimed in claim 3 wherein R3 is a C1-C10 alkyl.

29. An oxygen-permeable lens as claimed in claim 4 wherein R3 is a C1-C10 alkyl.

30. An oxygen-permeable lens as claimed in claim 4 wherein the fluorocarbon group is from about 2 to about 20 fluorine atoms.