Figure 3.

The range of eccentricities (relative to the foveal line-of-sight) accessible in human subjects. Y axis is pupil aspect ratio which defined as entrance pupil diameter in horizontal meridian divided by entrance pupil diameter in vertical meridian. The broken line with triangle symbol indicates the theoretical prediction of this ratio by cosine law. Shaded zone indicates a range of acceptable values equal to (number of raw spots in horizontal meridian ±1 /number of raw spots in vertical meridian ±1). The black lines connecting asterisk symbols indicate the actual pupil aspect ratio estimated from the number of illuminated lenslets for each subject.