Anatomy, Physiology, and Pathology of the Organs of Hearing, Vision, and Speech - A.G. Shvetsov 2006

Anatomy, Physiology, and Pathology of the Visual Analyzer

A living creature has no truer or more reliable helper than the eye. To see is to distinguish friend, foe, and surroundings in every detail. Other Senses perform the same function, but in a comparatively cruder and weaker manner. The common saying 'we shall see' reflects the idea that seeing is believing. It is in this sense that we must understand the saying of Anaxagoras: 'Sight is a manifestation of the unseen.' Through Vision, the invisible world becomes a reality, a tangible phenomenon.

Vision (visio, visus) is the physiological process of perceiving the size, shape, and color of objects, as well as their relative position and the distance between them.

The Visual sensory system is the most important sensory system in humans and most higher vertebrates. It provides over 80% of the information reaching the Cerebral Cortex from all receptors. Moreover, the eye is the only sense organ for which the distance from the perceived object does not matter; as a unique distant receptor, it detects emitted or reflected light from a source at any distance, whether it be stars in the night sky or the text of a book. Indeed, the olfactory and auditory systems, although also distant by The Nature of their stimulus perception, are limited in range and lack precise capabilities for localizing the source of a scent or sound. The eye is capable of seeing in both dazzling sunlight and near-total darkness, integrating millions of light signals. It distinguishes an immense variety of color shades, and with the help of the other eye, it can assess THE POSITION OF an object in space, its volume, and its configuration. Strictly speaking, however, all these remarkable properties belong not to the eye itself as an Organ of vision, but to the visual analyzer, particularly its cortical division located in the Brain.

In addition, the eyes are a prominent feature of the face and, to some extent, a source of information about a person; it is not without reason that they are called the 'mirror of the soul'.