An anopsia () is a defect in the

visual field The visual field is "that portion of space in which objects are visible at the same moment during steady fixation of the gaze in one direction"; in ophthalmology and neurology the emphasis is mostly on the structure inside the visual field and it i ...

. If the defect is only partial, then the portion of the field with the defect can be used to isolate the underlying cause. It is particularly used to describe the lack of sight in one eye.

Variants

Types of partial anopsia include: *

Hemianopsia Hemianopsia, or hemianopia, is a loss of vision or blindness ( anopsia) in half the visual field, usually on one side of the vertical midline. The most common causes of this damage are stroke, brain tumor, and trauma. This article deals only wi ...

Homonymous hemianopsia Hemianopsia, or hemianopia, is a visual field loss on the left or right side of the vertical midline. It can affect one eye but usually affects both eyes. Homonymous hemianopsia (or homonymous hemianopia) is hemianopic visual field loss on the s ...

** Heteronymous hemianopsia ***

Binasal hemianopsia Binasal hemianopsia is the medical description of a type of partial blindness where vision is missing in the inner half of both the right and left visual field. It is associated with certain lesions of the eye and of the central nervous system, ...

***

Bitemporal hemianopsia Bitemporal hemianopsia is the medical description of a type of partial blindness where vision is missing in the outer half of both the right and left visual field. It is usually associated with lesions of the optic chiasm, the area where the opt ...

** Superior hemianopia ** Inferior hemianopia *

Quadrantanopia Quadrantanopia, quadrantanopsia, refers to an anopia (loss of vision) affecting a quarter of the visual field. It can be associated with a lesion of an optic radiation. While quadrantanopia can be caused by lesions in the Temporal lobe, tempora ...

References

External links

Visual disturbances and blindness {{eye-stub