Figure 2.

Pupil response curve to selected wavelength light stimulation for one healthy subject. The stimulus is a 470 or 660 nm light at 300 cd/m² presented continuously for 20 s. The broken line represents the reference line of baseline pupil size. The normalized pupil size is displayed as a function of time for the blue light stimulus (blue line) and red light stimulus (red line). The pupil contraction is rapid, lasts approximately 2 s for both blue and red light stimuli and reaches maximum contraction at approximately the fourth second. The pupil remains contracted to blue light until the light termination (20th second), whereas pupillary escape is observed during red light stimulation.