[Optical characteristics of the human eye].
The optical characteristics of the eyeball are caused by its non-coaxial system. We show that the refraction changes throughout an individual's life. Results were obtained by a longitudinal study for ten years on patients (from 3-year-old to 58-year-old, 254 eyes of 127 persons) with only ametropia. We also did a longitudinal study for two years of healthy 3-year-old children (54 eyes of 27). However, we could not define the factors which control the refraction change. We examined the alteration of refraction induced by examination circumstances such as the size, shape, direction of fixation targets, and brightness of the room. Only minimizing size caused an increase of deviation range of astigmatism axis with miosis. Concerning a moving target from 5 m to 0.5 m, anisometropic eyes with the retinal conjugate point nearer to the target tended to track the target more closely than isometropic eyes.
Department of Ophthamology, Nara Medical University, Japan.
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Saishin
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D012029:Refraction, Ocular