Correction of defects in the eye and compositions therefor

A composition for forming in vivo a lens in the eye of a human being or other animal, said composition being substantially curable at body temperature to form a lens which is optically clear and remains so in the presence of physiological fluids, said composition being free of filler material and comprising:

• (a) a crosslinkable organosiloxane polymer containing crosslinkable hydrogen or alkenyl groups and having the average formula:
• ##STR14## wherein:
• M is a monofunctional, silicon-containing, chain capping residue;
• D is a difunctional, siloxane monomer unit, T is a trifunctional, siloxane monomer unit;
• and Q is a tetrafunctional siloxane monomer unit;
• and m and n are average numbers whose total is from about 2 to about 1000, n being a positive number greater than zero, m being zero or a positive number greater than zero;
• the average degree of polymerization of said polymer being from about 100 to about 20,000, the value of said degree of polymerization and m and n determining the average value of x;
• (b) an organosiloxane crosslinker polymer containing alkenyl groups when polymer (a) contains said crosslinkable hydrogen groups or hydrogen groups when said polymer (a) contains said crosslinkable alkenyl groups, polymer (b) having at least one of the following general formulae (i), (ii) and (iii):
• ##STR15## wherein the R substituents are substituted or unsubstituted and are the same or different and are selected from the group consisting of alkyl, aryl, alkaryl and aralkyl;
• R.sup.1 is hydrogen or alkenyl;
• and q is an average number from about 1 to 250 times the value of q', q' being an average number of from about 3 to 20;
• the material of Formula VIII having an average degree of polymerization of from about 50 to 5,000, the average value of q being determined by the difference between the degree of polymerization and the average value of q';
• ##STR16## wherein M is a monofunctional, silicon-containing, chain-capping residue;
• D is a difunctional siloxane monomer unit;
• T is a trifunctional siloxane monomer unit;
• and
• Q is a tetrafunctional siloxane monomer unit;
• and
• wherein n and x are average positive numbers, m is 0 or an average positive number, the total of n+m being from about 2 to 100 and, when m=0, n alone has these values, the degree of polymerization (DP) being from 50 to 5,000;
• and ##STR17## wherein R and R.sup.1 are as defined above, n is an average number substantially equal to the average degree of polymerization of the material which is from about 50 to 5,000;
• and
• (c) a platinum complex catalyst capable of promoting a crosslinking reaction between said hydrogen or alkenyl groups in polymer (a) and said alkenyl or hydrogen groups in polymer (b).