Patent ID: 8211955

Claim:
A soft contact lens, comprising a silicone hydrogel material that is obtained by curing a lens-forming material in a mold, wherein the lens-forming material comprises at least one actinically crosslinkable prepolymer and is substantially free of vinylic monomers and crosslinking agent with molecular weight of less than 1500 Daltons, wherein the prepolymer comprises poly(oxyalkylene) blocks, polysiloxane blocks and actinically-crosslinkable groups, wherein the prepolymer is obtained by copolymerizing a mixture comprising (1) at least one linear poly(oxyalkylene) with two first reactive groups, (2) at least one linear polysiloxane with two second reactive groups, (3) a branched poly(oxyalkylene) with multiple first reactive groups, a branched polysiloxane with multiple second reactive groups, or combination thereof, and (4) optionally a hetero difunctional compound having one ene-containing group and one first or second reactive group, wherein the first and second reactive groups, different from each other, are either thiol groups or acryl groups and undergo Michael addition reaction to form carbon-sulfur bonds, wherein the formed soft contact lens has an elastic modulus of from about 0.2 MPa to about 2.0 MPa and a water content of from about 15% to about 80% by weight when the formed soft contact lens is fully hydrated.