will be immersed in the compositions for a time sufficient to disinfect the lenses this immersion will typically be accomplished by means of soaking the lenses in a solution overnight i e approximately six to eight hours the lenses will then be rinsed and placed in the eye prior to immersion in the disinfecting compositions the lenses will preferably also be cleaned and rinsed the compounds of formula i also have surface active properties as a result of these properties the compounds are also useful in cleaning contact lenses more specifically the surfactant properties of the compounds facilitate the removal of deposits typically accumulated on contact lenses when worn by human patients these deposits vary from patient to patient but will typically include proteins lipids polysaccharides and mixtures thereof as well as various other soils which may accumulate on the lenses during normal wear and handling the compounds will exhibit some cleaning effect even at the relatively low concentrations required for purposes of preserving ophthalmic compositions or disinfecting contact lenses this cleaning effect is therefore useful as a supplement to the effect of other cleaning agents which may be contained in the compositions such as anionic or nonionic surfactants moreover when used at a concentration of 0 01 wt or higher the compounds exhibit a more pronounced cleaning effect the manner in which the cleaning effect of the compounds of formula i is utilized will depend on the type of contact lens being treated the severity and type of the deposits on the lenses and the overall treatment regimen used by the patient the selection of other components for inclusion in the.