Cast moulding technique in contact lens
The present invention relates to improvements in static cast molding of contact lenses. A method known, in general, for manufacturing contact lenses is static cast molding. Cast moulding technology of contact lenses involves depositing a curable mixture of polymerizable monomers in a mold cavity formed by two mold sections, curing the monomer mixture, and disassembling the mold assembly and removing the lens. One mold section forms the anterior lens surface (anterior mold section), and the other mold section forms the posterior lens surface (posterior mold section). Prior to the cast molding contact lens , each of the mold sections is formed. Conventional methods involve injection molding the molds sections from a resin in the cavity of an injection molding apparatus. Typically, the mold sections are used only once for casting a lens and then discarded. Several cast molding methods have been found to offer the potential to reduce production time and cost for the manufacture of sof...