Behavioural characteristics of children with permanent cortical visual impairment.

The common behavioral features of 50 children with permanent cortical visual impairment (CVI) are described. CVI is frequently associated with specific behavioural characteristics. The majority of these children have residual vision, but they all have variable and inconsistent visual performance, including visual acuity. They see better in familiar environments and when they understand what to look for and where to look for it. They often use touch to identify objects. Their ability to identify colours is much stronger than their perception of form. Many turn their heads to the side when they are reaching. Nystagmus and visual self-stimulation are exceptionally rare. They appear to have great difficulty with the cognitive evaluation of visual perception in spatial terms. Head elevation is worst in those with least vision, and without head elevation the possibility of visual stimulation is further restricted.