Dimensionally stable silicone hydrogel contact lenses

摘要

Dimensionally stable silicone hydrogel contact lenses are described. The lenses are derived from a polymerizable composition including a first siloxane monomer represented by formula (1): wherein m of formula (1) represents one integer from 3 to 10, n of formula (1) represents one integer from 1 to 10, R1 of formula (1) is an alkyl group having from 1 to 4 carbon atoms, and each R2 of formula (1) is independently either a hydrogen atom or a methyl group; the lenses also include units derived from a second siloxane monomer represented by formula (2): wherein R1 of formula (2) is selected from either hydrogen atom or a methyl group; R2 of formula (2) is selected from either of hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m of formula (2) represents an integer of from 0 to 10; n of formula (2) represents an integer of from 4 to 100; a and b represent integers of 1 or more; a+b is equal to 20-500; b/(a+b) is equal to 0.01-0.22; the configuration of siloxane units includes a random configuration, the second siloxane monomer having a number average molecular weight of at least 3,000 daltons that is present in the polymerizable composition in an amount such that ratio of the first siloxane monomer to the second siloxane monomer is at least 2:1 based on unit parts by weight. Batches of silicone hydrogel contact lenses and methods of making silicone hydrogel contact lenses are also described.