PURPOSE: To report a case of combined cilioretinal artery and central retinal vein occlusion in a patient with extremely large, asymptomatic optic disc drusen. METHODS: A patient with sudden vision loss underwent a comprehensive examination, including multimodal imaging. RESULTS: A 45-year-old man with no previous visual symptoms presented with a combined cilioretinal artery and central retinal vein occlusion in the right eye. The optic nerve in the right eye was slightly hyperemic and the nerve appeared normal in the left eye. His optic nerves did not have a nodular appearance but showed subtle hyperautofluorescence. A hematological and clotting work-up was unrevealing. Optical coherence tomography revealed an exceptionally large, deeply embedded optic disc druse (1604 x 1390 μm) that almost spanned the width of the optic canal, starting from 464 μm beneath the optic disc surface extending to below any visible lamina cribrosa. The right eye demonstrated a paracentral scotoma, while a minimal visual field defect was observed in the left eye despite the presence of a large-sized (1125 x 803 μm) druse. CONCLUSION: While optic disc drusen are typically small nodular aggregates in the prelaminar optic nerve head, this patient had an enormous buried solitary druse of the optic nerve in each eye. The unexpected size and location of the drusen, along with the lack of preceding symptoms, suggest that they may not be detected in routine evaluations, thus necessitating multimodal imaging. The redundancy of nerve fibers in the optic nerve may allow significant asymptomatic damage prior to vascular occlusion.