A 28-year-old woman presented with complaints of acute-onset severe bursting headache with vomiting for 7 days and pain, redness, swellingof eyelids, andbulgingof the right eye for 2days. She had a history of treatment for rhinosinusitis 15dayspriorwhen she received625mgoforal augmentin (amoxicillin and clauvalanic acid) 3 times daily for 10 days based on culture sensitivity (Staphylococcus aureus) of purulent discharge from the right sphenoidal sinus. On examination, she had severe chemosis with a ballooned-outpalpebral conjunctivawith visible pulsation,marked eyelid edema, and proptosis of the right eye (Video). Visual acuity was finger counting in the right eye and 6/6 in the left eye. Bilateral pupils were normal in size and shape and reacted well to light. Fundus examination of right eye showed optic disc edema and retinal hemorrhages suggestive of central retinal venous occlusion, but it was normal in the left eye (Figure, D). There was mild restriction of extraocular movements in all directions in the right eye. Magnetic resonance images of the brain were suggestive of right-sided cavernous sinus thrombosis Video at jamaneurology.com