| abstract |
A contact lens of a crosslinked, organic aprotic solvent insoluble, substantially transparent polymer of a derivative of a polyvinyl alcohol having a weight average molecular weight of at least about 2,000, containing an effective amount between about 0.1 and 90 percent, based on the number of hydroxyl groups on said polyvinyl alcohol, of a crosslinked addition reaction product of units of the formulan in the presence or absence of a polymerizable vinylic monomer wherein R 1 is a divalent aliphatic, cycloaliphatic, aryl, aralkyl or alkaryl group; A is -O-, -NH- or -NHCON(R")- where R" is hydrogen or lower alkyl and A' is a direct bond; or A is a direct bond and A' is -O-or -0-CH 2 -; R 2 is hydrogen or methyl; and R is hydrogen, methyl or -COOR 4 where R 4 is hydrogen or lower alkyl; with the proviso that if R 2 is methyl, R 3 is hydrogen; and wherein the polymerizable vinylic monomer, if present, is hydrophobic or is a mixture of hydrophobic and hydrophilic vinylic monomers in which mixture at least 50 % of vinyl monomers are hydrophobic. |