A simple mechanism for emmetropization without cues from accommodation or colour

Vision Res. 1994 Apr;34(7):873-6. doi: 10.1016/0042-6989(94)90037-x.


We propose and test the simple hypothesis that a chicken eye can emmetropize without cues derived from accommodation or colour just by maximizing retinal image contrast. Using different translucent occluders with known modulation transfer functions we found that deprivation myopia is correlated with the amount of image degradation. Equipped with a long-term integrator, a mechanism minimizing image degradation by changing the axial eye growth rate would therefore be sufficient to place the plane of focus of the eye at the average viewing distance.

Publication types

  • Letter
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Accommodation, Ocular
  • Animals
  • Chickens
  • Contrast Sensitivity / physiology
  • Myopia / physiopathology
  • Pattern Recognition, Visual / physiology
  • Refraction, Ocular*
  • Retina / physiology*
  • Sensory Deprivation / physiology