To provide a surface treatment method for a hydrous contact lens which improves the water wettability (hydrophilic properties) of the lens without affecting its characteristics, improves its durability and exhibits excellent characteristics in lipid contamination resistance, and to provide a hydrous contact lens, which has excellent characteristics, obtainable by the method.

In this method, the hydrous contact lens made of a copolymer at least containing a (meta)acrylamide-based monomer is subjected to plasma treatment in an oxygen gas and/or carbon dioxide gas atmosphere.