Abstract: This invention provides a method of manufacturing a contact lens comprising the step of: dosing a contact lens mold comprising optical mold surfaces with an oxygen-sensitive reaction mixture, wherein said optical surfaces of said contact lens mold have between from 0.13×10−9 to 2.6×10−9 moles/cm2 O2 available to interfere with the reaction of said reaction mixture. This invention further provides a method of manufacturing a contact lens comprising the steps of: dosing a contact lens mold comprising optical mold surfaces with a reaction mixture, and sealing said reaction mixture and said optical mold surfaces away from a gaseous environment, wherein said optical surfaces of said contact lens mold were exposed to said gaseous environment comprising greater than 0.5 percent oxygen just prior to said sealing step.