Persistent Link:
http://hdl.handle.net/10150/289763
Title:
Purkinje images for optical assessment of lenticular surfaces
Author:
Hall, Heidi Leising
Issue Date:
2001
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The optical properties of Fresnel reflections from the human ocular surfaces, called Purkinje reflections, are examined. Extensive modeling of the behavior of the reflection of sources from the front of the cornea and the front of the crystalline lens with real rays in lens design software is presented. The modeling looks at the effects of various conic constant values on the ocular surfaces and rotation of the eye in particular. First and third Purkinje images were collected from 14 subjects for varying fixation positions to compare with modeling. The results showed a decrease in third Purkinje image height as the eye rotated from gazing at a point near the light sources to a point near the optical axis of the imaging camera. This matched the predictions from modeling and indicates that fixation position is an important factor in the accuracy and repeatability of comparison phakometry results. Schematic eye models were set up for each subject and the anterior lens radius of curvature and conic constant were optimized to match the collected Purkinje image height data. The mean conic constant estimate from optimization was -3.82 with a standard deviation of 1.51. The schematic eye models did not include crystalline lens tilt or individual corneal conic constant values, each of which is estimated to contribute an uncertainty of ± 0.5 in the anterior lens conic constant value. This is the first use of Purkinje images to assess anterior lens conic constant values.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Health Sciences, Ophthalmology.; Physics, Optics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Optical Sciences
Degree Grantor:
University of Arizona
Advisor:
Greivenkamp, John E.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titlePurkinje images for optical assessment of lenticular surfacesen_US
dc.creatorHall, Heidi Leisingen_US
dc.contributor.authorHall, Heidi Leisingen_US
dc.date.issued2001en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe optical properties of Fresnel reflections from the human ocular surfaces, called Purkinje reflections, are examined. Extensive modeling of the behavior of the reflection of sources from the front of the cornea and the front of the crystalline lens with real rays in lens design software is presented. The modeling looks at the effects of various conic constant values on the ocular surfaces and rotation of the eye in particular. First and third Purkinje images were collected from 14 subjects for varying fixation positions to compare with modeling. The results showed a decrease in third Purkinje image height as the eye rotated from gazing at a point near the light sources to a point near the optical axis of the imaging camera. This matched the predictions from modeling and indicates that fixation position is an important factor in the accuracy and repeatability of comparison phakometry results. Schematic eye models were set up for each subject and the anterior lens radius of curvature and conic constant were optimized to match the collected Purkinje image height data. The mean conic constant estimate from optimization was -3.82 with a standard deviation of 1.51. The schematic eye models did not include crystalline lens tilt or individual corneal conic constant values, each of which is estimated to contribute an uncertainty of ± 0.5 in the anterior lens conic constant value. This is the first use of Purkinje images to assess anterior lens conic constant values.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectHealth Sciences, Ophthalmology.en_US
dc.subjectPhysics, Optics.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorGreivenkamp, John E.en_US
dc.identifier.proquest3040152en_US
dc.identifier.bibrecord.b42565856en_US
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