Table 2.

Description of each pupillary variable calculated

Variable Name (units)	Definition
Baseline Pupil Diameter (pixels)	Median pupil diameter in the 30 s preceding light onset
Phasic Constriction (% from baseline)	Median % constriction between 300–700 ms after light onset
Constriction Latency (s)	Time required after light onset for the pupil to reach 10% of constriction
Maximum Pupil Constriction (% from baseline)	$1-\frac{\text{Min Pupil Diameter (during light on)}}{\text{Baseline Pupil Diameter}}$
Sustained Slope (%/s)	Slope of best fit linear regression from 3–10 s after light onset
Post-Illumination Pupil Response (PIPR, % from baseline)	Median percent constriction between 5 to 7 s after light offset
Area Under the Curve (AUC, %.s)	Absolute value of a trapezoidal numerical integral of the data between light offset and 12 s after light offset