We report two patients, both with a history of gastric surgery, who presented with progressive optic neuropathy and myelopathy. The patients' symptoms were initially attributed to vitamin B12 deficiency and/or neuromyelitis optica; however, after the neurologic deficits continued to progress with the use of conventional treatments, further evaluation was initiated, and a severe copper deficiency was revealed. Copper deficiency is a rare cause of progressive optic neuropathy and myelopathy and should be considered in the differential diagnosis. It is crucial to elicit a history of gastric surgery or other risk factors for hypocupremia in those patients undergoing an evaluation for subacute or chronically progressive optic neuropathy or myelopathy.