Determination of ocular defocus using the double-pass blur image of a point source

Nainesh K. Gandhi, Kenneth J. Mandell, David L. Guyton, David G. Hunter

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A double-pass blur circle from a point source can be used to determine the quality of focus of the human eye. An apparatus that can determine a threshold of defocus was devised. A circle/annulus (`bulls-eye') photodiode that can distinguish focused from defocused light was used. The photodetector signal obtained was a function of the amount of defocus caused by the double-pass point spread reflected from the retina. The signal will thus be affected by refractive error, incomplete accommodation, media opacities, and abnormalities of retinal reflection. Such defocus detection can be combined with eye-fixation monitoring to be used as a screening tool to detect risk factors for amblyopia.

Original languageEnglish (US)
Title of host publicationAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
PublisherIEEE
Number of pages1
ISBN (Print)0780356756
StatePublished - Dec 1 1999
EventProceedings of the 1999 IEEE Engineering in Medicine and Biology 21st Annual Conference and the 1999 Fall Meeting of the Biomedical Engineering Society (1st Joint BMES / EMBS) - Atlanta, GA, USA
Duration: Oct 13 1999Oct 16 1999

Publication series

NameAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
Volume2
ISSN (Print)0589-1019

Other

OtherProceedings of the 1999 IEEE Engineering in Medicine and Biology 21st Annual Conference and the 1999 Fall Meeting of the Biomedical Engineering Society (1st Joint BMES / EMBS)
CityAtlanta, GA, USA
Period10/13/9910/16/99

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ASJC Scopus subject areas

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics

Cite this

Gandhi, N. K., Mandell, K. J., Guyton, D. L., & Hunter, D. G. (1999). Determination of ocular defocus using the double-pass blur image of a point source. In Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings (Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings; Vol. 2). IEEE.