What term describes the phenomenon when one pupil contracts as a response to light in the other pupil?

The term that describes the phenomenon when one pupil contracts as a response to light in the other pupil is known as consensual reaction. This physiological response occurs due to the neural pathway that connects both sides of the brain, allowing the constriction of one pupil in reaction to light exposure in the other eye. It is part of the reflex arc that controls pupillary size, known as the pupillary light reflex.

The consensual reaction is important in clinical settings as it helps assess the integrity of the optic nerve and the pathways involved in pupil response. When light is shone in one eye, both pupils typically constrict, demonstrating the consensual response.

Other terms like direct reaction refer specifically to the response of the same eye that is exposed to light, accommodation relates to the adjustment of the eye's lens for focus, and photophobia is a sensitivity to light, which does not pertain to pupillary response. Understanding these distinctions is crucial in examinations of neurological function and ocular health.