A new semi-automatic videopupillometer with a two-channel video integrator uses prismatic displacement of pupil images for binocular recording with a single infrared-sensitive video camera. The video integrator graphically records pupil area or diameter during testing and can reanalyze and plot information from videotape recordings of pupil responses.This new pupillometer was used to evaluate the pupil dark response in 178 eyes of 89 normal human volunteers (ages 18–75 years). The time course of pupil dilation was similar in volunteers of all ages, even though the average pupil area became progressively smaller with increasing age.