Amblyopia is a reduction in the quality of central, corrected vision resulting from a disturbance in retinal image formation during the first decade of human life. Although the neurophysiology and neuropathology of amblyopia are now better understood than in the past, treatment has not changed significantly in more than 200 years. The earlier amblyopia is detected, the shorter the duration of treatment required to reduce its severity. The mainstay of treatment still consists of forcing the use of the amblyopic eye, most often by occlusion of the sound eye. Complications of treatment include occlusion amblyopia and induction of strabismus in straight-eyed patients.