Extended wear rigid gas permeable lenses used for correction of aphakia

A study of extended wear rigid gas permeable lenses in aphakic patients was started in 1975. We present an analysis of 186 patients (274 eyes) with from 1 to 194 months (average: 88 months) of extended wear. Patients wore their lenses 24 hours per day, only removing the lenses for periodic cleaning. Approximately one-third of the patients removed their lenses at least once per week; roughly another one-third wore lenses for up to a month between cleanings; and one-third cleaned lenses at intervals up to 6 months. All of the patients in the study achieved vision with their contact lenses comparable to their best spectacle correction without an overcorrection. None of the patients experienced a permanent loss of vision as a result of this mode of contact lens wear.