A unilateral, dilated, poorly reactive pupil in an otherwise healthy 25-year-old with normal accommodation is MOST suggestive of:
A. Third nerve palsy
B. Pharmacologic mydriasis
C. Adie’s tonic pupil ✔️
D. Argyll Robertson pupil
Explanation: Adie’s tonic pupil shows light-near dissociation (poor light response, better near response) due to ciliary ganglion damage. It’s typically unilateral, benign, and occurs in healthy young adults. Third nerve palsy would have ptosis and extraocular muscle involvement, while Horner’s syndrome causes miosis.