What it means
The opening in the iris. It gets smaller (constricts) in bright light and when looking at something close, and larger (dilates) in dim light and with fear or excitement. Pupil checks are part of every neurological exam: size, shape, equality and reaction to light. Opioids make pupils small; some drugs and brain injuries make them large.
For the nurse
Check both pupils with a penlight and record their size in millimeters and how they react. A pupil that becomes larger, oval or slow to react, especially on one side, can mean rising pressure in the skull and must be reported at once.
Remember it
PERRLA: pupils equal, round, reactive to light and accommodation.
At a glance
| Spanish | pupila |
|---|---|
| Also written | pupillary |
Related terms
intracranial pressure
The pressure inside the skull, made by the brain, the blood and the fluid around the brain.
consciousness
The state of being awake and aware of oneself and one's surroundings.
optic nerve
The nerve that carries visual signals from the back of the eye to the brain; the second cranial nerve.
cornea
The clear, dome-shaped layer at the front of the eye, over the iris and pupil.