Tinted contact lens and method of manufacture thereof: reactive dye and quaternary phosphonium salt

摘要

An improvement in a process for preparing a contact lens tinted over at least a portion of its surface, having the steps of forming a tinting solution having a reactive dyestuff and applying the tinting solution to a polymeric hydrogel contact lens material, wherein the improvement comprises adding an effective amount of an ammonium or phosphonium quaternary salt to the tinting solution before the applying step.