Stable polyvinyl alcohol hydrogel contact lens and preparation thereof

A dimensionally stable hydrogel contact lens of polyvinyl alcohol having an equilibrium water content of between about 70 and about 80 weight percent, based upon the total swollen lens weight, said lens having been annealed in a mold essentially conforming to the contact lens dimensions under substantially ambient non-drying setting conditions in the presence of an aqueous-organic annealing promoter solvent, for a period of time substantially sufficient to reach annealing equilibrium.