This invention relates generally to disinfection and cleaning systems for medical devices. In a preferred embodiment, the invention relates to compositions, methods and articles for simultaneously cleaning and disinfecting contact lenses. The present invention is directed to ophthalmic compositions containing one or more block copolymers referred to as (polyoxyethylene)-(poly-oxybutylene) block copolymers (“PEO-PBO”). The invention is particularly directed to the use of PEO-PBO di-block copolymers as non-foaming wetting agents in peroxide-based compositions for disinfecting contact lenses.