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Journal of the Optical Society of America A

Journal of the Optical Society of America A


  • Editor: Franco Gori
  • Vol. 27, Iss. 7 — Jul. 1, 2010
  • pp: 1541–1548

Correlation between radius and asphericity in surfaces fitted by conics

Alfonso Pérez-Escudero, Carlos Dorronsoro, and Susana Marcos  »View Author Affiliations

JOSA A, Vol. 27, Issue 7, pp. 1541-1548 (2010)

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The optical surfaces of the eye are often described in terms of their radius and asphericity. The variations caused by experimental noise in repeated measurements of radius and asphericity of the same surface are strongly correlated. We show this correlation in experimental corneal elevation data from videokeratoscopy and Scheimpflug topography, in non-contact profilometry data of artificial lenses, and in simulations. The effect is a characteristic of the fits to conic curves, and not restricted to any experimental device or fitting procedure. A separate analysis of radius and asphericity may estimate incorrectly the statistical significance of the changes in the ocular surfaces. We propose a MANOVA-based statistical analysis that increases sensitivity by a factor of 4.

© 2010 Optical Society of America

OCIS Codes
(330.4875) Vision, color, and visual optics : Optics of physiological systems
(330.7325) Vision, color, and visual optics : Visual optics, metrology

ToC Category:
Vision, Color, and Visual Optics

Original Manuscript: December 23, 2009
Revised Manuscript: March 20, 2010
Manuscript Accepted: May 3, 2010
Published: June 2, 2010

Virtual Issues
Vol. 5, Iss. 11 Virtual Journal for Biomedical Optics

Alfonso Pérez-Escudero, Carlos Dorronsoro, and Susana Marcos, "Correlation between radius and asphericity in surfaces fitted by conics," J. Opt. Soc. Am. A 27, 1541-1548 (2010)

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