Amblyopia is characterized by a drop in certain visual aptitudes in the absence of any detectable ocular cause. It can affect one or both eyes. It appears in early childhood, even from birth, and requires early attention. A strabismus in a child is most likely a sign of amblyopia and an ophthalmological exam must be planned. It can be caused by an eye infection or an accommodation problem (myopia, hyperopia, strabismus). Amblyopia can be corrected by wearing glasses, the occlusion of the unaffected eye, or surgical treatment. Amblyopia in adults is rarely treated.