At the 2014 American Academy of Ophthalmology Annual Meeting (AAO) Pediatric Ophthalmology Session, Professor Eileen E Birch of the University of Texas Southwestern Medical Center elaborated on a new understanding of strabismus, namely that children with amblyopia have a structurally intact binocular visual system but only monocular function, which may shed some new light for ophthalmologists. Amblyopia occurs if there is an imaging inconsistency during visual development, usually associated with strabismus and/or refractive error. If one eye is habitually suppressed (suppression), monocular visual deficits (i.e., amblyopia) can occur quickly. The onset of amblyopia is accompanied by a series of visual function decreases that lead to spatial aberrations, hypermetropia, ocular fixation instability, and fine motor abnormalities. Masking therapy and the application of atropine are the main methods of treatment for amblyopia. More than 80% of children with amblyopia have significantly improved visual acuity in the amblyopic eye after masking and/or atropine treatment. However, masking and the application of atropine did not treat binocular abnormalities. This may explain why only 40% of children treated with masking or atropine recovered to 20/20 vision, while more than 30% experienced a recurrence of amblyopia. The visual cortex is primarily responsible for the processing of visual information and the fusion of binocular input. Binocular information fusion and stereopsis require a balance of visual sensitivity, visual acuity, and mutual inhibition. In amblyopia, this balanced interaction is broken, with the amblyopic eye giving a weak noise signal and mild inhibition to the contralateral eye, and the dominant eye strongly inhibiting the amblyopic eye. The prevailing theory is that suppression is a necessary change for adaptation, and that suppression prevents visual confusion and diplopia due to strabismus or refractive aberrations. However, several lines of evidence suggest that interocular suppression imbalances play an important role in the development of amblyopia and the occurrence of visual and motor abnormalities associated with monocular vision loss. Based on these new interpretations of the role of interocular inhibition, Professor Eileen E Birch et al. suggest that inhibition may be a stumbling block to the successful treatment of amblyopia. Recently, the predominant theory of visual development has also proposed that the immature primary visual cortex (V1) fails to establish a strong connection with the inhibited amblyopic eye during the critical period of visual maturation. The failure to establish a strong connection leads to changes in ocular dominance, and once the critical period is over, the amblyopic visual system is considered to be established and its structurally altered in one eye. These beliefs have been recognized to be false, and in fact, V1 matures earlier, and its distribution in terms of ocular dominance remains normal even if infantile strabismus or refractive aberrations have occurred. The occurrence of V1 and V2 neuronal inhibition in both eyes correlates with the degree of amblyopia. In other words, the imbalance of inhibition between the two eyes results in a structurally intact binocular visual system that is only functionally available in one eye. The new evidence that the binocular visual system in children with amblyopia is structurally intact but only functionally available in one eye broadens the field of amblyopia research and supports the development of more effective evidence-based treatment measures. If interocular inhibition imbalance plays an important role in the development of amblyopia, can restoring interocular inhibition balance again be used as a treatment for amblyopia? The answer is yes, by allowing the amblyopic eye to “break through” and reduce the imaging difference with the contralateral eye, allowing the amblyopic child to see binocularly. The children with amblyopia can wear anaglyphic red-greenglasses to play the game at home while also receiving treatment. By playing the off-eye iPad game and repeatedly using both eyes to see, the vision of children with amblyopia can be effectively improved.