Effective corneal refractive zone in terms of Gaussian optics
Accepted 26 July 2008.
The portion of the cornea that transmits light for vision is clinically important in several contexts, including corneal ablation in refractive surgery. In contrast to geometric optics, Gaussian optics allows one to obtain simple, explicit formulas for the geometry of the effective corneal refractive zone for distant object points that are on or off the line of sight. In this article, Gaussian optics was used to derive the formula for the diameter of the zone and, when the zone is annular, the inner and outer diameter, as a function of corneal power, anterior chamber depth, pupil diameter, and angular position of the object point.
From the University of Johannesburg, Johannesburg, South Africa
Corresponding author: William F. Harris, PhD, Department of Optometry, University of Johannesburg, Auckland Park Campus, PO Box 524, Auckland Park, 2006 South Africa.
The author has no financial or proprietary interest in any material or method mentioned.
The University of Johannesburg, Johannesburg, South Africa provided financial support.
E. Kruger and S. M. Brown reviewed the manuscript.
ABSTRACT