Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

The refractive state of the feral and domestic chicken eye under normal and prolonged exposure to light.

Abstract

Laboratory reared White Leghorn-Black Australorp crossed birds had an inferior refractive state compared with feral birds, and their eyes changed by several dioptres from a hypermetropic state over two months from hatching and seldom reached emmetropia in adulthood. Rearing under constant 24-h and 12-12-h lighting conditions showed that a permanent refractive disorder, astigmatism, due to corneal distortion, could be induced by continuous incandescent illumination.