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26 August 2004 New shape of videokeratometric illuminator - comparison with cylindrical one
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Proceedings Volume 5566, Optical Security and Safety; (2004) https://doi.org/10.1117/12.577218
Event: Optical Security and Safety, 2003, Warsaw, Poland
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.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Damian Siedlecki and Henryk T. Kasprzak "New shape of videokeratometric illuminator - comparison with cylindrical one", Proc. SPIE 5566, Optical Security and Safety, (26 August 2004); https://doi.org/10.1117/12.577218
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