Blindsight in children: does it exist and can it be used to help the child? Observations on a case series

Damage to the occipital lobe of the brain results in hemianopia when unilateral, and cerebral blindness when bilateral. However, in some cases a degree of visual function persists in the blind visual field. This aim of this study was to describe this phenomenon of 'blindsight' in a cohort of children with brain-damage and to relate the clinical features to their visual evoked potentials. We performed a retrospective analysis of 541 case records of children referred to a tertiary vision-assessment clinic in the Royal Hospital for Sick Children, Glasgow, UK from 1992 to 2002. A total of 541 patients were analyzed (243 females, 298 males; age range 2 mo to 19 y 6 mo, mean 6 y 2 mo). In 19 children with profound visual impairment and four children with hemianopia (12 females, 11 males; age range 1 to 18 y, mean age 8 y 3 mo), evidence of perception of movement in the blind visual field was found and is described. Flash visual evoked potentials varied from no response to normal and was not correlated with visual behaviour. Recognition, detection, and use of this phenomenon in children is vital to their rehabilitation and interaction with their surroundings.