A NEW SCHEMATIC EYE THAT ACCURATELY MODELS HUMAN SPHERICAL AND CHROMATIC ABERRATION

Title A NEW SCHEMATIC EYE THAT ACCURATELY MODELS HUMAN SPHERICAL AND CHROMATIC ABERRATION
Author, Co-Author Ming Ye, Xiaoxiao Zhang, Larry Thibos, Arthur Bradley
Topic
Year
1992
Day
Sunday
Program Number
Poster 48
Room
Great Hall
Affiliation
Abstract Optical models of the human eye can be very complex if they strive to be both optically and anatomically correct. An alternate approach employs the simplest optical model with little emphasis on anatomical accuracy. Such models (e.g. Gullstrand's and Emsley's reduced model eyes) can provide computational simplicity and accurate models of retinal image quality. For example, the recent 'chromatic eye' proposed by Thibos et al (1992) accurately predicts ocular transverse and longitudinal chromatic aberration. Our new model eye is a modification of the 'chromatic eye' which has a single refracting surface, and a uniform optical medium. To achieve spherical aberration consistent with that observed in unaccommodated humans, the shape of the single refracting surface has been modified from an ellipse which, for distant targets, exhibits zero spherical aberration. Using wave optics we have determined that a surface of Y= 0.0899X^2 + 0.0005X^4 provides a spherical aberration function similar to that observed in human eyes. For example, at a pupil eccentricity of 3mm, the new schematic eye exhibits 1.54 D of positive spherical aberration, whereas the chromatic eye exhibits zero, and Emsley's reduced eye has 5.79 D. Previous experimental measures of spherical aberration of human eyes (e.g. Ivanoff, 1956; Francon, 1951; Schober, 1968; and Koomen, 1949) are well fit by this model at all beam eccentricities.
Affiliation of Co-Authors
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