Visual impairments can result from problems with any part of the visual system including the eyes,eye muscles, optic nerve and the areas of cerebral cortex that process visual information. Optic nerve damage, visual field losses , and cataracts are common in premature infant with retinopathy of prematurity. Children with cerebral palsy exhibit a variety of problems with acuity and focusing, oculomotor performance and visual perception.
Almost 75 % children have refractive errors including near sightedness or farsightedness + astigmatism.Cortical visual impairment is defined as partial or total blindness due to injury in the visual pathway or visual cortex of the brain rather than in the eye itself.
Visual perception the process of obtaining information from the environment which includes discrimination, memory, spatial relationship, form constancy, sequential memory, figure ground and closure.Children with cerebral palsy have been found to score significantly lower then normal children on motor-free tests of visual perceptual skills.