Pupil light reflex will be measured by a pupillometer in response to short and long wavelength light small spot stimulus in different area of the visual field. The PRL will be measured in four quadrant, central, 10, 20, and 30 degree from the visual axis.
Stimulus duration will be 1000 ms (1 sec), with intervals of 890 ms between stimuli. The stimuli size V with light intensity of 39.8 cd-s/m2 for both short wavelength stimuli (peak 485 nm) and long wavelength stimuli (peak 620nm).
