Contact lenses are disinfected by utilizing an N-alkyl-2-pyrrolidone as the microbicide. The efficacy of prior art microbicides such as chlorhexidene gluconate are enhanced by the addition of the pyrrolidones of this invention. The pyrrolidones suitable for use in the practice of this invention are the C.sub.8 -C.sub.20 N-alkyl-2-pyrrolidones. Preferably the alkyl moiety is octyl, decyl or dodecyl. The pyrrolidones can be utilized in solution or made available as a water soluble tablet.