Figure 3
Simulation of measurements of Mathur and colleagues 2013. (A) A camera was positioned 100 mm from the cornea at different viewing angles within the temporal and nasal visual field. The line-of-sight of the eye was aligned with the optical axis of the camera at a viewing angle of zero. (B) The output of the current model is shown for equally spaced (30°) viewing angles from the temporal to nasal visual field. In the center image, viewed at −5°, the optical axes of the eye and camera are nearly aligned in the horizontal plane. The points shown correspond to the vitreous chamber (white), visible iris border (blue), entrance pupil border points and fitted ellipse (green), front corneal surface (yellow), and the center of the aperture stop (red plus). The iris border and pupil border points are virtual images, having been subjected to refraction from the cornea. Iris border points are missing in some views as these points encountered total internal reflection during ray tracing. (C) The pupil diameter ratio (PDR) is the ratio of the minor to the major axis of an ellipse fit to the entrance pupil. θ is the tilt of the major axis of the pupil ellipse. This value of θ is the empirically observed tilt of the entrance pupil ellipse, which is not to be confused with the specified value θ that is the modeled tilt of the elliptical aperture stop in Eq. 3.
