A probationary essay on the anatomy and physiology of the eye : submitted, ... to the examination of the Royal College of Surgeons of Edinburgh, ... / by John Argyll Robertson ... February, 1822.

  • Robertson, John Argyll, 1798 or 1799?-1855.
Date:
1822
Catalogue details

Licence: Public Domain Mark

Credit: A probationary essay on the anatomy and physiology of the eye : submitted, ... to the examination of the Royal College of Surgeons of Edinburgh, ... / by John Argyll Robertson ... February, 1822. Source: Wellcome Collection.

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    n Tiie 0£tic Nerves, the medium of communication between the eye and brain, are generally described as arising from the thalami nervorum opticorum: but, ac¬ cording to Winslow, Santorini, Gall, and other anato¬ mists, from the nates and testes. They are large, and of a whiter colour than the other nerves, and are covered bv the Dura Mater and Pia Mater. They consist (like other nerves) of small fibres running parallel to each other. These fibres are chiefly evident in that part of the nerve which is situated between the sella turcica and eye. The Optic nerves approach each other at the sella turcica, and appear to intermingle the one with the other. But Ana¬ tomy has not yet enabled us to determine whether they merely touch or whether they are intimately mixed. Some authors suppose that the fibres cross each other, and that the nerve, issuing from the brain on the right side, crosses over to the left eye, and vice versa. Pathology does not settle the question; for when the right eye is diseased, • the optic nerve of the right side is sometimes found dis¬ eased in all its length, and in other cases the anterior part only of the right side and posterior of the left. These nerves enter the eyeball nearer the nose than the axis of the orbit, and are somewhat contracted at their entrance. They then expand into a nervous membrane called Retina. The Retina is a thin nervous membrane nearly trans¬ parent, of a slight milky colour, thickest at its origin from the nerve, and situated between the choroid, and hyal- oide, or membrane of the vitreous humour. It has a yel¬ low spot about two lines from the nerve towards the ex¬ ternal angle. This membrane runs forward as far as the capsule of the crystalline humour, and is supplied with blood-vessels by the Arteria Centralis Retinae.