It is an object of the present invention to provide a contact lens solution that imparts stable hydrophilicity even to a surface of a contact lens having strong water repellency. There was prepared a contact lens solution comprising a copolymer of N-p-vinylbenzyl-D-lactonamide and at least one monomer copolymerizable therewith. The copolymer is present in the solution in an amount of 0.0001 to 5 w/v %.