HEMIANOPSIA - loss of half (or a quarter) of the visual field. It is usually observed with organic lesions of the visual pathway (with brain tumors, traumatic brain injury, etc.). Distinguish between the same and unlike hemiopia. With the same name hemianopsia, the same sides of the visual field of both eyes fall out - right or left. For unlike hemianopsia, the loss of either the internal or external visual fields of both eyes is characteristic. Hemianopia is an important diagnostic sign of the lesion of a particular part of the visual pathway. It may be a permanent or temporary symptom, depending on the nature and severity of the visual pathway.