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Proceedings Paper

New null screen design for corneal topography
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Paper Abstract

In this work we report the design of a null screen for corneal topography. Here we assume that the corneal surface is an ellipsoid with a diameter of 12 mm and a curvature radius of 7.8 mm. To avoid the difficulties in the alignment of the test system due to the face contour (eyebrows, nose, or eyelids), we design a conical null-screen with spots (similar to ellipses) drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact radial array of circular spots if the surface is perfect. Additionally, we performed a numerical simulation introducing Gaussian random errors in the coordinates of the centroids of the spots on the image plane, and in the coordinates of the sources (spots on the null-screen) in order to obtain the conical null-screen that reduces the error in the evaluation of the topography.

Paper Details

Date Published: 25 October 2011
PDF: 9 pages
Proc. SPIE 8011, 22nd Congress of the International Commission for Optics: Light for the Development of the World, 801124 (25 October 2011); doi: 10.1117/12.903397
Show Author Affiliations
Manuel Campos-García, Univ. Nacional Autónoma de México (Mexico)
Amilcar Estrada-Molina, Univ. Nacional Autónoma de México (Mexico)
Rufino Díaz-Uribe, Univ. Nacional Autónoma de México (Mexico)


Published in SPIE Proceedings Vol. 8011:
22nd Congress of the International Commission for Optics: Light for the Development of the World
Ramón Rodríguez-Vera; Ramón Rodríguez-Vera; Ramón Rodríguez-Vera; Rufino Díaz-Uribe; Rufino Díaz-Uribe; Rufino Díaz-Uribe, Editor(s)

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