It’s a natural body reaction for direct focus, much how human beings will also squint in order to adjust their focus and attention on a specific coordinate.
My guess is that for Hunters, their optics do the same to give them greater accuracy for firing Flechettes and successful ramming attacks against targets.
"The pupil of your eye can expand as much as 45% while looking at someone you love." Hunters when they see Gordon:
i thought those were weapons and the small spheres near them were the eyes, so i assume the shrinking would be some form of accuracy adjustment
It’s a natural body reaction for direct focus, much how human beings will also squint in order to adjust their focus and attention on a specific coordinate. My guess is that for Hunters, their optics do the same to give them greater accuracy for firing Flechettes and successful ramming attacks against targets.