2-Pyrrolidinone, 1-ethenyl-, polymer with methyl 2-methyl-2-propenoate, 2-propenyl 2-methyl-2-propenoate and 1,2-ethanediyl bis(2-methyl-2-propenoate); 56551-60-1 Lidofilcon A Lidofilcon A [USAN] Lidofilcon B Lidofilcon B [USAN]