Certified Ophthalmic Assistant Practice Exam

The consensual light reflex in the right eye results in what reaction from the left pupil?

1. Left pupil dilation

2. No change

3. Left pupil constriction

4. Left pupil oscillation

The correct answer is: Left pupil constriction

The consensual light reflex refers to the phenomenon where shining a light into one eye not only causes that eye's pupil to constrict but also causes the pupil of the opposite eye to constrict. This reflex is mediated by the optic nerve, which transmits sensory information from the retina to the brain, where the signals are coordinated to produce a bilateral constriction of the pupils. When light is directed into the right eye, it stimulates the photoreceptors in the retina. The information is transmitted to the brain, which processes it and sends motor signals through the oculomotor nerve to both the right and left pupils. As a result, the left pupil also responds by constricting. This coordinated response illustrates the functioning of both the neural pathways involved and the integrated reflex mechanisms of the eye. In contrast, the other responses do not occur in this reflex scenario. Dilation of the left pupil would be inconsistent with the consensual response, and no change would not reflect the normal parasympathetic pathway activation that occurs. Oscillation is unrelated to this reflex and pertains to other types of ocular motor responses.