The eyes of young chickens grow toward emmetropia.
The distribution of refractive errors was followed in chicks from hatching to 8 weeks of age. A dramatic progressive decrease in the variability of refractions was observed over this period. In addition, there appeared to be a parallel decline in hyperopia, even when the artifactual hyperopia of retinoscopy was taken into account. These results are evidence for a postnatal development regulatory mechanisms, most likely dependent on vision, which directs growth of the eye toward emmetropia.
D000818:Animals; D002645:Chickens; D005123:Eye / Q000196:embryology / Q000254:growth & development*; D006956:Hyperopia / Q000151:congenital; D012030:Refractive Errors / Q000151:congenital*; D014785:Vision, Ocular