Visual impairment among people with developmental delay.

The prevalence of visual impairment (V.I.) has been described in people living in large institutions, but there is no information about the prevalence among all adult people with developmental delay (D.D.). The present study shows that the prevalence is 10-fold that of adults without D.D. Caregivers have difficulties in assessing V.I., hence professional examinations for all are necessary. Many V.I. people with D.D. simply need corrective spectacles. V.I. people with D.D. often have additional disabilities, thus 50% of patients with optic nerve atrophy or with cortical V.I. have epilepsy, cerebral palsy or both. Half the individuals with D.D. and V.I. were unable to speak, walk alone or feed themselves.