A water extractable ophthalmic device is disclosed which is a polymerization product of a monomeric mixture comprising: (a) one or more cyclic lactams; (b) one or more organosilicon-containing block copolymers; (c) one or more bulky siloxane monomers; and (d) a crosslinking agent mixture comprising (i) one or more first crosslinking agents containing at least two ethylenically unsaturated reactive end groups, wherein the at least two ethylenically unsaturated reactive end groups are (meth)acrylate-containing reactive end groups and (ii) one or more second crosslinking agents containing at least two ethylenically unsaturated reactive end groups wherein at least one of the ethylenically unsaturated reactive end groups is a non-(meth)acrylate reactive end group. The water extractable ophthalmic device has an equilibrium water content of at least about 50 wt. %, a contact angle of less than about 50°, and an oxygen permeability of at least about 60 Barrers.