SUDDEN, complete binocular loss of vision in a healthy young adult is undoubtedy a major catastrophe to the patient. When examination of the afflicted person reveals no pathologic basis for the blindness, it becomes a problem of major importance to the ophthalmologist. Such is often the case in the rare syndrome called neuromyelitis optica, or Devic's disease.1 This condition is commonly ushered in by sudden, total blindness, followed by a severe, rapidly ascending inflammation of the spinal cord, terminating in death. The cause of this malady is unknown, and there is no known method of effective therapy. Pathologically, acute necrosis of nerve tissue is observed, principally in the optic nerves and the spinal cord. Histologically, destruction of myelin sheaths, axis-cylinders, nerve cells and neuroglia is seen, accompanied with infiltration of white blood cells and with a feeble attempt at repair by the nerve tissue. Neuromyelitis optica is but one