Which consensual response normally occurs when shining a light in the right eye?

When a light is shone into one eye, the normal consensual response is constriction of both pupils, but specifically regarding the left pupil, it will constrict in response to light in the right eye due to the neural pathways at play.

This reflex is part of the pupillary light reflex, where the optic nerve receives the light stimulus and transmits the signal to the pretectal nucleus in the midbrain. The signal is then sent to both Edinger-Westphal nuclei on both sides, leading to constriction of the pupils in both eyes, regardless of which eye the light is directed toward. As a result, shining light in the right eye leads to both the right eye's pupil constricting and the left eye's pupil also constricting as a consensual reaction.

Understanding this response is crucial as it helps in assessing the function of the retinal and brain pathways responsible for vision and reflexive actions. It highlights the interconnectedness of the visual system and the importance of accurate assessment in clinical practice.