Patent ID: 7820082

Claim:
A method for forming a photochromically-enabled bifocal overmold layer on an optical lens injection molding machine having a vertical equipment axis, comprising the steps of: injecting molten thermoplastic resin into an edge-gated lens-forming cavity, opening the mold at a time when a single vision (SV) lens is rigid enough to maintain its shape while being retained on the lower mold half, and swapping out the SV upper mold half; swapping in a bifocal upper mold half having a base curve closely matched to the SV lens; depositing an unpressurized full metered charge of a photochromically-enabled thermoset composition on to the upwardly-facing convex surface of the SV lens; and clamping the bifocal upper mold half to the lower mold half, whereby the thermoset composition is thermally cured by the heat from the mold and the residual heat from the thermoplastic lens to form a photochromically-enabled bifocal shaped overmold lens that is intimately formed on the thermoplastic SV lens.