title: Effects of experimentally induced ametropia on the morphology and optical quality of the avian crystalline lens.
abstract: OBJECTIVE
  To examine the effects of refractive error on avian lens morphology and optical quality.
  
  
  METHODS
  Hatchling white leghorn chicks were unilaterally goggled for 7 days with either a form-deprivation goggle (n = 12), a -10 D defocus goggle (n = 12), or a +10 D defocus goggle (n = 12) to induce myopia and hyperopia. Optical quality of lenses (focal length and focal length variability) from treated and contralateral control eyes was assessed using a scanning laser apparatus. Lens morphology was examined by light and electron microscopy.
  
  
  RESULTS
  Although the induction of refractive errors did not significantly alter lens size, shape, paraxial focal length, or average focal length, average focal length variability increased. Lenses from eyes goggled with form-deprivation and +10 D defocus goggles demonstrated a twofold increase in average focal length variability, when compared with their contralateral controls. The morphology of the lens is not altered by these experimental manipulations.
  
  
  CONCLUSIONS
  This study provides evidence that the refractive development of the chick lens is not independent of the refractive development of the ocular globe and that chick lenticular development is influenced by both genetics and visual experience.
authors.affiliation: School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Priolo
authors.forename: J G
authors.initials: JG
authors.lastname: Sivak
authors.forename: J R
authors.initials: JR
authors.lastname: Kuszak
authors.forename: E L
authors.initials: EL
authors.lastname: Irving
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002645:Chickens; D006956:Hyperopia / Q000209:etiology / Q000503:physiopathology*; D007908:Lens, Crystalline / Q000503:physiopathology* / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D009216:Myopia / Q000209:etiology / Q000503:physiopathology*; D012683:Sensory Deprivation