Patent ID: 8003024

Claim:
A method of producing soft cast-molded contact lenses having reduced optical distortion, the method comprising: providing first and second mold members structured to be assembled together to form a lens-shaped cavity therebetween, each of the first and second mold members comprises a nucleated thermoplastic polyolefin resin having a melt flow rate in a range from about 20 g/10 min to about 40 g/10 min as measured using test method ASTM D1238 at conditions of 230° C. with a load of 2.06, wherein an amount of nucleating agent is about 0.1% to about 1.5% (wt/wt); providing a contact lens-forming composition in the cavity; forming a cast-molded contact lens product from the contact lens-forming composition in the cavity; removing the cast-molded contact lens product from the first and second mold members; and repeating the providing, placing, forming and removing steps a plurality of times to produce a plurality of soft cast-molded contact lens products having reduced optical distortion relative to an identically produced plurality of soft cast-molded contact lens products made using first and second mold members comprising a thermoplastic olefin resin having a melt flow rate of 1.9 g/10 min; wherein the reduced optical distortion of the lenses comprises a reduced number of lenses with optical distortions that are visually apparent at 28× magnification using a knife edge optical system, as determined using an interferometer and wavefront analysis.