Note 15 — THE DREAMS OF THE BLIND

Dr. Heermann's observations also enable us to trace the anatomical conditions underlying the power of dream-vision. From ten cases in which post-mortem examinations were held, he concludes that, allowing for much individual difference, after about twenty years the optic nerves degenerate, and often as far back as the chiasma. This shows that the nerve is not necessary for dream-vision, and thus goes to prove that the process is dependent on cerebral organs—a valuable piece of evidence fifty years ago. Esquirol records a case of sight-hallucinations in a blind woman, again indicating the same conclusion.