Schematic diagram of the pupillary light response illustrating the recorded pupillary light reflex parameters.

1) maximal pupil diameter, 2) minimal pupil diameter, 3) pupil constriction ratio, 4) constriction latency, 5) average constriction velocity, 6) maximal constriction velocity, 7) average dilation velocity, 8) total time taken by the pupil to recover 75% of maximal pupil diameter.