Reduced eye

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Structure of the eye. The incident light is refracted several times at the media transitions between air and cornea, the water in the anterior chamber, the lens and the vitreous humor

The reduced eye , also called the normal eye , is a schematically simplified model of the average human eye in physiological optics ( reduced schematic eye or collapsed dioptric system of the eye ). It was developed by the Swedish medic Allvar Gullstrand .

The optical system of the real human eye is adapted to the optical density of the surrounding medium air . It is made up of components with different radii and different refractive indices and consists of the cornea , lens , vitreous humor and aqueous humor in the anterior chamber between the cornea and lens.

Medium of propagation Refractive index radius distance Refractive power
Cornea 1,376 −7.7 mm 0.0 mm +43 dpt
Eye chamber 1,376 +6.8 mm 3.6 mm −3 dpt
lens 1,414 +10.0 mm 7.2 mm +19 dpt
Vitreous 1,336 −6.0 mm 24.4 mm

This complex structure results in a total refractive power of about 59 D, ​​which corresponds to a focal length of f = 1/59 D = 17 mm. For approximate calculations, the human eye of an adult can be approximated by a simple lens with a refractive power of 59 D or a focal length of 17 mm, provided that the ciliary muscle is relaxed (remote accommodation) .

literature

  • Rainer Klinke , Stefan Silbernagl (Ed.): Textbook of Physiology. 4th, corrected edition. Thieme, Stuttgart et al. 2003, ISBN 3-13-796004-5 , p. 607.
  • Kenneth N. Ogle: Optics. An Introduction for Ophthalmologists. Thomas, Springfield IL 1961, pp. 103, p. 163.