Which condition may cause hemianopia?

Hemianopia refers to a visual field loss on one side of the vertical midline of the visual field. A cerebrovascular accident (CVA), commonly known as a stroke, is one of the leading causes of hemianopia. A stroke can damage the areas of the brain responsible for processing visual information, particularly the occipital lobe and the optic pathways. When these areas are affected, it can lead to either homonymous hemianopia, where the same side of the visual field in both eyes is affected, or other forms of visual field loss depending on the location and extent of the stroke.

In contrast, hypertension, diabetes, and asthma do not directly cause hemianopia. While diabetes can lead to various eye problems, such as diabetic retinopathy, it does not typically result in hemianopia. Hypertension can have some impact on overall eye health and vision but does not usually cause the specific type of visual field loss associated with hemianopia. Asthma, being a respiratory condition, is unrelated to visual field changes. Thus, a cerebrovascular accident is the condition among those listed that is most directly associated with causing hemianopia.