This study is designed to evaluate the effectiveness of adding a plano lens to weekend atropine after visual acuity has stabilized with weekend atropine but amblyopia is still present. Children ages 3 to <8 years with visual acuity of 20/50 to 20/400 in the amblyopic eye will be enrolled in a run-in phase with weekend atropine until no improvement, followed by randomization of eligible patients to weekend atropine treatment with a plano lens over the sound eye versus without a plano lens over the sound eye. The primary objective is to determine if adding a plano lens to weekend atropine will improve visual acuity in patients with amblyopia still present after visual acuity has stabilized with initial treatment.