When inspecting a patient’s pupils with a penlight, the normal reaction is:

When inspecting a patient’s pupils with a penlight, the normal reaction is:

• A. Constricting
• B. Dilating
• C. Staying the same size
• D. Moving erratically

Answer: (A)

Shining a light into the eye should trigger a constriction of the pupil. This pupillary light reflex happens when light hits the retina and sends a signal via the optic nerve to the brain, which then sends a parasympathetic signal through the oculomotor nerve to the iris sphincter muscle, making the pupil smaller. In a normal, healthy patient, the pupil that you shine the light in constricts directly, and the other pupil constricts as well (the consensual reflex). If the pupil doesn’t constrict, or if it dilates or moves erratically in response to light, that points to potential neurological or ocular issues.

Shining a light into the eye should trigger a constriction of the pupil. This pupillary light reflex happens when light hits the retina and sends a signal via the optic nerve to the brain, which then sends a parasympathetic signal through the oculomotor nerve to the iris sphincter muscle, making the pupil smaller. In a normal, healthy patient, the pupil that you shine the light in constricts directly, and the other pupil constricts as well (the consensual reflex). If the pupil doesn’t constrict, or if it dilates or moves erratically in response to light, that points to potential neurological or ocular issues.