Methods for generating chlorine dioxide and compositions for disinfecting

A tablet for cleaning and disinfecting contact lenses comprising an outer layer comprising a proteolytic enzyme in an amount in the range of about 0.001 to about 5 Anson units, and an inner core encapsulated in a delayed release component which acts to delay the release of the inner core for at least about fifteen minutes after the tablet is placed in an aqueous medium, wherein the inner core comprises a chlorine dioxide precursor capable of generating chlorine dioxide when exposed to a transition metal in an amount sufficient to generate at least 0.1 ppm of chlorine dioxide, a transition metal component, and a buffering component effective to maintain the pH of the aqueous medium in which the tablet is released in the range of about 6 to about 10, said buffering component being effective to increase the rate of chlorine dioxide generation from said chlorine dioxide precursor relative to a similar tablet without said buffering component.