The use of poly(oxybutylene)-poly(oxyethylene)-poly(oxybutylene) 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, but do not induce foaming when used in conjunction with a peroxide-based contact lens disinfection regimen. Such compounds may also be useful for cleaning purposes. The use of the compounds as surfactants in peroxide-based compositions for disinfecting contact lenses therefore represents a preferred embodiment of the present invention.