A 6-year-old boy visited his local emergency department with a history of sudden painless bilateral visual loss. He was otherwise in good health apart from a history of chickenpox 8 weeks previously. His father had been treated for culture-negative mediastinal tuberculosis a year earlier. Initial examination in the emergency department showed visual acuity of counting fingers OU, a moderate bilateral panuveitis, and diffuse bilateral retinal edema with sheathing of both retinal arteries and veins. The optic discs were not swollen. Neurological examination findings were otherwise normal. Initial management aimed to treat a possible tuberculosis optic neuropathy and/or vasculopathy, using oral prednisolone, rifampin, pyrazinamide, and isoniazid. Initial investigations showed no abnormality on hematology and biochemistry tests of peripheral blood. Cytomegalovirus and VZV IgG were both detected on testing of serum, but polymerase chain reaction results for the respective DNA were negative. Evidence of tuberculosis infection was not found, with negative results on both enzyme-linked immunosorbent spot and Heaf tests and normal findings on chest radiography. Magnetic resonance imaging demonstrated no abnormal enhancement in the brain or chiasm, with normal optic nerve appearances. During the next week, visual acuity deteriorated to light perception OU. Panuveitis with retinal vascular sheathing (Figure 1A) persisted, with patchy areas of reperfused retina observed peripherally in the left eye on fluorescein angiography (Figure 1B). Doppler ultrasonography showed no detectable flow in central retinal artery or central retinal vein. Polymerase chain reaction results for a vitreous biopsy specimen were negative for both VZV DNA and tuberculosis. Electrophysiology showed a completely undetectable electroretinogram in both eyes, indicative of loss of outer retinal photoreceptor function and thus not in keeping with dysfunction confined to central retinal artery or vein circulation (Figure 2A). Magnetic resonance angiography showed a mostly normal cerebral vasculature but neither ophthalmic artery could be visualized (Figure 2B), in keeping with the electrophysiological data. Subsequently, VZV IgG was detected in cerebrospinal fluid, confirming VZV as the likely cause of the vasculopathy. Despite a course of systemic acyclovir and intravenous methylprednisolone, he maintains visual acuity of light perception OU.