The anatomy and physiology of the optic nerve: historical notes

The authors outline the historical development of anatomical and physiological acquisitions on the optic nerve. From the first descriptions of Alcmaeone of Crotone (6th century B.C.) through the Aristotelean school, we arrive at the systemization of Claudius Galen. After the medioeval parenthesis, it fell to Vesalius to give a new impulse to anatomical research. Varolio and Eustachi describe the exact point of origin of the optic nerves. Later observations involve both anatomists and physiologists. The question of the transmission of sensory messages is described (Willis, von Haller), as is the microscopic structure of the optic nerve (Zinn, von Leeuwenhoek). After the description of the decussation of the fibers of the optic nerve in the optic chiasma, research into this cranial nerve has an increasingly neurophysiological and neurochemical orientation, continuing until the recent discovery of axoplasmic flow.