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Journal of the Optical Society of America A

Journal of the Optical Society of America A


  • Vol. 15, Iss. 6 — Jun. 1, 1998
  • pp: 1500–1511

Light-intensity distribution in eccentric photorefraction crescents

Reinhard Kusel, Ulrich Oechsner, Wolfgang Wesemann, Stephan Russlies, Eva M. Irmer, and Bernhard Rassow  »View Author Affiliations

JOSA A, Vol. 15, Issue 6, pp. 1500-1511 (1998)

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We try to improve the accuracy of eccentric photorefraction by taking more information into account than just the size and tilt of the crescent. Based on Gaussian optics and the assumption of an isotropic scattering retina, a theoretical analysis of the light-intensity distribution in the pupils of astigmatic eyes is presented. The method is applied to different photorefractor setups (point light source, long linear light source, knife-edge aperture, and circular aperture). In the case of a knife-edge aperture the crescent structure can be formulated analytically. In the case of a circular aperture an analytic description is possible only for spherical refractive errors, but astigmatic refractive errors can be determined from crescent parameters with neural networks.

© 1998 Optical Society of America

OCIS Codes
(000.1430) General : Biology and medicine
(170.4460) Medical optics and biotechnology : Ophthalmic optics and devices
(220.2740) Optical design and fabrication : Geometric optical design
(330.4300) Vision, color, and visual optics : Vision system - noninvasive assessment

Original Manuscript: August 19, 1997
Revised Manuscript: January 16, 1998
Manuscript Accepted: February 4, 1998
Published: June 1, 1998

Reinhard Kusel, Ulrich Oechsner, Wolfgang Wesemann, Stephan Russlies, Eva M. Irmer, and Bernhard Rassow, "Light-intensity distribution in eccentric photorefraction crescents," J. Opt. Soc. Am. A 15, 1500-1511 (1998)

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