Figure 1

Schematic of the model eye. The components of the model are shown for an emmetropic right eye that is focused on a point 3 meters distant. The lens, cornea, vitreous chamber, and the aperture stop of the iris are aligned and centered on the optical axis (dotted line). The model specifies the location of the fovea (asterisk). Two rays are shown that connect the fovea to the fixation point. The visual axis (gray line) is a nodal ray of the optical system. The line of sight (pink line) passes through the center of the entrance pupil.