<unk>  can be congenital, but is usually caused by brain injury such as from stroke, trauma, tumors, infection, or following surgery. Vascular and neoplastic (malignant or benign tumours) lesions from the optic tract, to visual cortex can cause a contralateral<unk> . Injury to the right side of the brain will affect the left visual fields of each eye. The more posterior the cerebral lesion, the more symmetric (congruous) the<unk>  will be. For example, a person who has a lesion of the right optic tract will no longer see objects on his left side. Similarly, a person who has a stroke to the right occipital lobe will have the same visual field defect, usually more congruent between the two eyes, and there may be macular sparing. A stroke on the right side of the brain (especially parietal lobe), in addition to producing a<unk> , may also lead to the syndrome of hemispatial neglect. Transient<unk>  does not necessarily mean stroke. For instance, it can constitute the aura phase of migraine. Concomitant presence of a moving scintillating scotoma is suggestive of migraine, but has been seen in cerebral cancer as well. Computed tomography (CT scan) or MRI can be used to investigate if stroke, tumor, structural lesion, or demyelination is the cause of<unk> .
Homonymous hemianopsia
Binasal hemianopsia
Agraphesthesia
Bitemporal hemianopsia
Lexical–gustatory synesthesia
Hemianopsia
Palinopsia
Finger agnosia