In this case discussion from Neuro-Ophthalmology Subspecialty Day 2011, Dr. Michael Johnson presents a case of arteritic anterior ischemic optic neuropathy (AAION): pallid optic disc edema in the affected eye, cotton-wool spots in the contralateral eye, and no systemic symptoms. A left temporal artery biopsy was positive for giant cell arteritis (GCA). This case illustrates several of the clinical features that may distinguish AAION—and “occult giant cell arteritis”—from NAION. Recognizing these features is particularly helpful when the patient history is noncontributory or confounding, and can help guide the ophthalmologist to appropriate, timely treatment of GCA.