A 58-YEAR-OLD man developed transient monocular visual loss in the right lower quadrant of the left eye that fully resolved in less than 24 hours. He was afebrile and had no other symptoms. His known medical history included well-controlled arterial hypertension and dyslipidemia. He denied a history of cerebrovascular disease, atrial fibrillation, intravenous drug use, and thromboembolic disease. Medical evaluation included a carotid Doppler ultrasound that showed no abnormality, an unremarkable brain magnetic resonance imaging (MRI) examination, an unremarkable ophthalmologic examination, and a normal white blood cell count.