The effect of age, size of target, and cognitive factors on accommodative responses of children with Down syndrome

PURPOSE. To investigate possible factors that may be implicated in the poor accommodative responses of individuals with Down syndrome. This article ev aluates the effect of age, angular size of target, and cognitive factors on accommodation. METHODS. Seventy-seven children with Down syndrome who are participating in an ongoing study of visual development were assessed. One hundred thirty-o ne developmentally normal children took part in a previous study and provid ed control data. Accommodation was measured using a modified Nott dynamic r etinoscopy technique. RESULTS. Children with Down syndrome showed considerably poorer accommodati ve responses than normally developing children. No target used in the prese nt study produced an improved response in children with Down syndrome. Age, angular subtense of target, and cognitive factors could not fully account for the poor accommodation in children with Down syndrome. CONCLUSIONS. Poor accommodation is a common feature of Down syndrome, regar dless of the target used. The etiology of the deficit has yet to be establi shed. It is imperative that educators and clinicians are aware that near vi sion is out of focus for these children.