One hundred sixteen strabismus patients with amblyopia treated with initial full-time or part-time conventional occlusion of the preferred eye followed when necessary with maintenance occlusion up to a maximum of nine years were studied. Based on the need for maintenance occlusion, patients were divided into a primary occlusion group, composed of patients who did not require maintenance occlusion and a maintenance group occlusion group, composed of patients who did require maintenance occlusion. The main difference between the two groups of patients was the degree of amblyopia at the onset of occlusion therapy, being significantly greater in the maintenance occlusion group. The maintenance occlusion group showed a significantly higher incidence of visual acuity regression when evaluated at ages 12 and 13 years. Occlusion therapy administered to strabismus patients in the manner described in this study resulted in significant visual improvement with a regression in visual acuity of no more than an average of one line on the Snellen chart.