The pupil opens and closes automatically in response to light what part of your nervous system controls this response

PNS controls this response

The portion of the system that's outside the brain and medulla spinals. Abbreviated PNS. The nerves within the PNS connect the central system (CNS) to sensory organs, like the attention and ear, and to alternative organs of the body, muscles, blood vessels, and glands.

Papillary response could be a physiological response that varies the scale of the pupil, via the optic and cranial nerve.