Mold for making contact lenses, the male mold member being more flexible than the female mold member

摘要

A plastic mold assembly comprising a male and female section for casting soft contact lenses from a polymerizable feed material wherein compensation for polymerization shrinkage is attained and disengagement of the male and female mold sections is facilitated by providing one flexible and one rigid mold section. Good optical properties of the mold surfaces are obtained by forming the mold sections entirely from a thermoplastic material such as polystyrene that will not crystallize when cooled from a melt. In one embodiment a plurality of flexible male sections having convex molding surfaces and a plurality of rigid female sections having concave molding surfaces are supported on frames to attain an increased production rate of finished soft contact lenses.