Prism induced accommodation in infants 3 to 6 months of age

Convergence-accommodation, one of several cross-linkages in the oculomotor system is manifested by opening the accommodative feedback loop and increas ing the vergence input. We elicited this response in human infants aged 3-6 months by placing a 15 Delta prism (base-out) before one eye while they vi ewed a diffuse patch of light. Accommodation was measured and ocular alignm ent was confirmed with a video photorefractor. The convergence-accommodatio n response is therefore present during a rime when blur driven accommodatio n and disparity vergence are maturing. The gain of convergence-accommodatio n (expressed as the stimulus CA/C ratio) appeared to be greater for infants than adults. (C) 2000 Elsevier Science Ltd. All rights reserved.