the use of poly - poly block copolymers in pharmaceutical compositions useful for modifying the surfaces of contact lenses and other medical devices is disclosed . the present invention is based in - part on a discovery that this class of compounds is particularly efficient in wetting hydrophobic surfaces , such as the surfaces of silicone hydrogel contact lenses and other types of ophthalmic lenses . such compounds are also useful for cleaning purposes . the use of the compounds as surfactants in various types of compositions for treating contact lenses therefore represents a preferred embodiment of the present invention .