Abstract: A polymer comprising quaternary ammonium salts and alkylene groups having hydroxyl groups on the main chain, is extremely useful as a disinfectant for ophthalmic apparatuses, as eye drops, and an eyewash solution as well as a cleaning solution, disinfectant, or storing solution for contact lens care. The polymer compound has sufficient bactericidal and fungicidal effects within a concentration range in which the compound causes no damage on human cells and does not irritate the eye as well as being hard to be absorbed, adsorbed, and accumulated on hydrophilic contact lenses. In addition, the compound is highly hydrophilic, and as a result, when the polymer is used for contact lens care, the lenses become favorably lubricated to be worn comfortably, and furthermore, is very gentle to eye.