Course of the visual path

The visual pathway extends from the retina of the eye to various areas of the brain. The most distant area of the brain is located at the back wall of the skull and thus at the head on the opposite side of the eyes. The beginning of the visual path is represented by the sensory cells of the retina, the rods and cones.

The first visible part of the visual path is formed by the emerging optic nerve, the optic nerve. This nerve is first visible at the back of both eyes. From there, the optic nerves run backwards and centrally through the eye socket and form the so-called optic chiasma, the intersection of the visual pathways, in front of the brain stem.

This is where the nasal fibers of the optic nerve cross. The nerve fibers are called tractus opticus in the further course. One optic tractus on each side opens into the diencephalon.

From here fibers lead to the primary and secondary visual cortex. The intersection of the visual pathways occurs at the point where the visual pathways of both eyes meet. This lies between the eye sockets and the brain stem.

At the intersection of the visual pathways, the central nasal nerve fibers cross over to the opposite side. The outer, temporal nerve fibers remain on their side and do not cross. After the intersection of the visual pathways, each visual pathways contains a portion of nasal and a portion of temporal nerve fibers. This means that the stimuli of the right half of the field of vision are processed in the left brain and the stimuli of the left half of the field of vision are processed in the right brain.

Function of the visual path

The visual pathway serves to transmit visual impressions and signals from the eye to the brain. The transport of this information converted into electrical signals is necessary to perceive the visual impressions. If the visual impressions were not transmitted to the cerebrum, we would not be able to perceive what we see.

The visual pathway is also linked to the sense of balance and control reflexes, among other things. If the impression of the eye differs from that of the organ of equilibrium, the positional reflexes compensate. On a ship that is swaying in the swell, both the eyes and the organ of equilibrium/vestibular organ perceive the fluctuations and activate the corresponding muscles so that we can continue to stand firm.