Word parts
What it means
Cranial nerve III. It controls four of the six muscles that move the eye, the muscle that lifts the upper eyelid, and the muscle that makes the pupilPYOO-pulThe round black opening in the center of the colored part of the eye, which lets light in.Full entry smaller in bright light. Damage to it can cause a drooping eyelid, double vision and a wide pupil that does not react to light. Swelling or bleeding in the brain can press on this nerve.
For the nurse
Check pupil size, shape and reaction to light (PERRLA) as part of a neurological assessment, and report a newly dilated or sluggish pupil right away.
Related terms
cranial nerve
One of the 12 pairs of nerves that come straight from the brain and brainstem rather than the spinal cord.
pupil
The round black opening in the center of the colored part of the eye, which lets light in.
increased intracranial pressure
Pressure inside the skull that has risen above the normal range.
PERRLA
Pupils equal, round, reactive to light and accommodation: charting shorthand for a normal pupil exam.