Hemianopsia
（重定向自Heteronymous hemianopsia）
![Paris as seen with full visual fields](/Images/godic/202501/18/Fullvf0612.png")
![Paris as seen with left homonymous hemianopsia.](/Images/godic/202501/18/Lhvf0612.png")
![Paris as seen with binasal hemianopsia.](/Images/godic/202501/18/Binasalvf0612.png")
![Paris as seen with bitemporal hemianopsia.](/Images/godic/202501/18/Bitempvf0612.png")
Hemianopsia, or hemianopia, is a decreased 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.