Cerebral/Cortical Visual Impairment: A Need to Reassess Current Definitions of Visual Impairment and Blindness.

Cerebral/cortical visual impairment (CVI) is characterized by higher order visual dysfunction caused by injury to the retrogeniculate visual pathways and brain structures which subserve visual processing. CVI has become the leading cause of significant vision loss in children in developed countries, but continues to be an under-recognized cause of visual disability with respect to services aimed at maximizing visual development. Current criteria which are used to define visual disability rely on measures of visual acuity and visual field. Many children who require specialized vision services do not qualify, because these standard definitions of vision impairment do not account for CVI. In order to appropriately identify patients with CVI and offer the resources which may positively impact functional use of vision, the definition of visual impairment and blindness needs to be modified. This commentary calls for a change in the definition of visual impairment and blindness to acknowledge those persons with brain-based vision impairment.