Insertion of the visual field

The retinal sections reflect the visual fields in opposite arrangement. The right part of the visual field of each eye is recorded on the left side of the retina. The left halves of the visual fields are accordingly imaged on the right part of the retina.The right and left tractus are switched in the midbrain.

From here, the so-called visual radiation moves into the cerebral cortex. It ends in the occipital lobe on the inner side of each of the two hemispheres in the visual center. You can find more information on the examination of the visual field under Examination of the visual field

What is the consequence of a failure of the visual path?

Injury to the visual pathway has always roughly formulated a complete or incomplete loss of the field of vision as a consequence. If the secondary visual cortex is affected, this results in a disturbance of the stimulus processing. Depending on the location of the injury, the loss of the field of vision takes different forms.

If the injury lies in front of the optic chiasm, a complete eye is lost. If the injury is located in the optic chiasm, the field of vision on the same side of both eyes is lost. If the visual path is injured after the optic chiasm, the loss of the field of vision can vary considerably.

The damage to the visual path can be divided into three sections: Prechiasmal, chiasmal and retrochiasmal diseases. In prechiasmal disease, the optic nerve is mainly affected. It results in a unilateral visual disturbance, such as blindness or loss of visual field, on the side of the respective lesion.

The chiasmal disease is located at the junction of both optic nerves, the so-called chiasma opticum. It usually occurs when a tumor of the pituitary gland (pituitary adenoma) presses on this structure. The patient then typically exhibits a so-called bitemporal hemianopsia, also known as blinker phenomenon, because the external visual field is missing on both sides. Retrochiasmal diseases describe damage that affects the sections after the union of both optic nerves. Homonymous hemianopsia is a typical clinical picture: Here the equilateral visual fields of both eyes are affected.