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

When a light is shone in one eye, a consensual response is observed where both pupils react to the stimulus. Specifically, shining a light in the right eye will cause the left pupil to constrict along with the right pupil. This phenomenon is known as the "consensual reflex," which demonstrates the interconnectedness of the pupils' responses due to neural pathways in the brain.

In the context of the question, the correct answer highlights the physiological response in which the left pupil responds to light entering the right eye. This is a normal response as both pupils constrict simultaneously even though only one eye is directly stimulated. The other options do not accurately reflect this reflex. For instance, dilation or unchanged pupil sizes would not constitute a proper consensual response when a light stimulus is applied, as the pupils typically do not behave in that manner under such conditions.