Measuring visual acuity in infants.

This paper reviews the course of development of visual acuity in human infants and young children. Researchers have devised methods based on optokinetic nystagmus, visually evoked cortical potentials and preferential looking to assess visual acuity in infants and preverbal youngsters. During the first postnatal year and early childhood, acuity, measured by any of these methods, improves with increasing age. Each of these methods, has now been applied to the evaluation of clinical cases. Also presented are the results of a quick and simple test based on preferential looking, which has been incorporated into our clinical evaluation of infants. The data so far indicate that infants with normal eyes pass the test while infants with ocular problems which would interfere with vision fail. For evaluation of large numbers of infants this test appears to have the potential to assist nonspecialized personnel in the early identification of ophthalmic abnormalities.