Figure 3.

Shows the schematic diagram of a PLR curve and illustrates each of the measured parameters. PLR parameters derived were: d_pup.init—The initial pupil diameter in a panel, d_pup.max—The maximum pupil diameter in a dilation panel, d_{pup.min (c)}—The minimum pupil diameter in a constriction panel, d_{pup.end (c)}—The pupil diameter at the end of a redilation period in a constriction panel, Δd (amplitude i.e. absolute values of changes)—The difference between d_pup.max or d_pup.min and the d_pup.init., Δt_dil—The time delay/latency for the initiation of dilation after light stimulation is off, Δt_con—The time delay/latency for the initiation of constriction after light stimulation is on, Δt_rec—The time delay/latency for the initiation of pupil redilation after the maximum constriction. T_dil, T_con, T_rec—The time constants (tau) representing the elapsed time required for the pupil to reach ~ 60% of its end value during dilation, constriction, and redilation.