The Hadju-Cheney syndrome is one of the idiopathic acroosteolyses. Associated neurologic abnormalities are often a result of progressive basilar invagination. A 48-year-old man with the Hadju-Cheney syndrome developed progressive bilateral visual loss. On examination, he had hyperopia, choroidal folds, optic nerve head swelling, and mild optic neuropathy. Computed tomographic scans showed massive enlargement of both intraorbital optic nerve sheaths. Improvement occurred after optic nerve sheath fenestration. Visual loss due to optic nerve meningocele can occur in the Hadju-Cheney syndrome. Optic nerve sheath fenestration can result in visual improvement. It is unclear whether the occurrence of optic nerve meningocele is causally or fortuitously related to the Hadju-Cheney syndrome.