What is the expected pupil response to a bright light?

What is the expected pupil response to a bright light?

• A. Dilates
• B. Remains unchanged
• C. Constricts
• D. Becomes irregular

Answer: (C)

Bright light triggers the pupil to constrict as part of the pupillary light reflex. When light hits the eye, the retina sends a signal that activates the parasympathetic pathway to the iris sphincter muscle, narrowing the pupil to limit light entry and protect the retina. In a normal response, both pupils constrict (the illuminated eye shows a direct response, and the other eye shows a consensual response). So the expected reaction is constriction. Dilation would let more light in, which is the opposite; remaining unchanged or becoming irregular would indicate a problem with the reflex pathway or neurological injury rather than a normal response.

Bright light triggers the pupil to constrict as part of the pupillary light reflex. When light hits the eye, the retina sends a signal that activates the parasympathetic pathway to the iris sphincter muscle, narrowing the pupil to limit light entry and protect the retina. In a normal response, both pupils constrict (the illuminated eye shows a direct response, and the other eye shows a consensual response). So the expected reaction is constriction. Dilation would let more light in, which is the opposite; remaining unchanged or becoming irregular would indicate a problem with the reflex pathway or neurological injury rather than a normal response.