What does the acronym PERRL stand for?

• A. Pupils equal, round, reactive to light
• B. Pupils equal, round, reactive to sound
• C. Pupils unequal, round, reactive to light
• D. Pupils round, reactive to light, not equal

Answer: (A)

PERRL is a quick bedside check of how the pupils respond to light, used to assess neurological status. It stands for Pupils equal, Round, Reactive to Light.

Pupils equal means both pupils are the same size; unequal pupils (anisocoria) can signal a localized nerve or brain issue. Pupils round describes their shape as normally circular rather than irregular. Reactive to light means there is a brisk constriction when light is shone in the eye, reflecting a functioning optic nerve (afferent pathway) and oculomotor nerve (efferent pathway) with a intact light reflex. If a pupil fails to constrict or constricts sluggishly, it can indicate nerve impairment or increased intracranial pressure. This check is especially useful in trauma to quickly gauge brainstem integrity and potential herniation signs. The option mentioning sound is incorrect because the test assesses light response, not auditory response.