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Proceedings Paper

New shape of videokeratometric illuminator - comparison with cylindrical one
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Paper Abstract

The aim of our study was to define such shape of videokeratometric Placido disc based illuminator that would guarantee quasi flat image formation and due to that sharp and reliable information of corneal geometry receiving. The new shape of surface, which Placido rings would be painted on, is "cigar" like and was the result of our model study. Now analytical comparison with existing, commercially used videokeratometric illuminator was performed. Such cylindrical illuminator is used in the Tomey TMS-3 videotopographer. The study relied upon simple analytical path of rays calculations. The calculations were performed for 17 rays in inproportionate configuration at the entrance pupil plane. The results show the difference between image surfaces created by both illuminators on the average cornea. The image surface formed by introduced stimulator is much more flatter than the image of TMS-3 illuminator. This means that in order to receive sharp images providing reliable data, one can use the camera with smaller depth of sharpness.

Paper Details

Date Published: 26 August 2004
PDF: 5 pages
Proc. SPIE 5566, Optical Security and Safety, (26 August 2004); doi: 10.1117/12.577218
Show Author Affiliations
Damian Siedlecki, Wroclaw Univ. of Technology (Poland)
Henryk T. Kasprzak, Wroclaw Univ. of Technology (Poland)

Published in SPIE Proceedings Vol. 5566:
Optical Security and Safety
Zbigniew Jaroszewicz; Ewa Powichrowska; Mariusz Szyjer, Editor(s)

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