A state of partial blindness in which someone has only half the usual field of vision in each eye.
Blindness to one half of the visual field in one or both eyes; also: hemianopsia.
Loss of vision in half of the normal visual field (right or left, top or bottom).
Blindness in half of the normal visual field. Hemianopia may affect one eye or both eyes. Whenever partial or complete blindness develops in one or both eyes, it is important to seek prompt medical attention. There are many possible reasons for the loss of sight, including injuries, diabetic retinopathy, macular degeneration, vitamin A (beta carotene) deficiency, retinitis pigmentosa, retinoblastoma, lead poisoning, glaucoma, trachoma, and progressive multifocal leukoencephalopathy (PML).
Absence of half of the normal field of vision. The commonest type is homonymous hemianopia, in which the same half (right or left) in lost in both eyes. Sometimes the inner halves of the visual field are lost in both eyes, producing a binasal hemianopia, while in others the outer halves are lost, producing a bitemporal hemianopia. Very rarely both upper halves or both lower halves are lost, producing an altitudinal hemianopia.
A term meaning loss of half the usual area of vision. The affected person may see everything clearly to the left or to the right, the field of vision stopping abruptly at the mid line; they may see things only when straight ahead of them; or, thirdly, they may see objects far out on both sides, although there is a wide area straight in front for which they are quite blind. The position of the blind area is important in localizing the position in the brain of the disease responsible for the condition.
Hemianopia refers to the loss of half of the visual field in each eye. This condition can be classified as “homonymous,” where the same side of both eyes is affected, or “heteronymous,” where the loss occurs on opposite sides of the eyes. The extent of visual loss can vary, and it may either be temporary or permanent.
Hemianopia is caused by damage to either the optic nerves or the brain. In young individuals, transient homonymous hemianopia is typically a result of migraines. However, in older individuals, it can occur during transient ischemic attacks, which are brief interruptions of blood supply to the brain. On the other hand, permanent homonymous hemianopia is usually linked to a stroke, but it can also arise from brain damage caused by tumors, injuries, or infections. Another possible cause of hemianopia is pressure on the optic nerve due to a pituitary tumor.
Loss of vision in half of the visual field, also known as hemianopsia.