Normal Findings
PERRL stands for pupils equal, round, and reactive to light. Normal pupils are about 3 to 5 mm and constrict equally when light is shone into them. Check one eye at a time and watch for the consensual response in the other.
Abnormal Findings
Dilated, fixed pupils can indicate severe brain injury, hypoxia, or cardiac arrest. Constricted pupils are classically associated with opioid use. Unequal pupils may signal increased intracranial pressure, stroke, or an old eye injury.
Clinical Use
Always consider context before drawing conclusions. Prosthetic eyes, cataract surgery, and certain medications can alter pupils. Document findings and reassess them as part of ongoing neurological monitoring.