Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Homonymous hemianopia
Introduction
Homonymous hemianopsia is a medical term for a type of partial blindness resulting in a loss of vision in the same visual field of both eyes.
Causes
Causes
It is usually caused by injury to the brain itself such as stroke or trauma, rather than malfunctioning of the eye itself.
Vascular and neoplastic (malignant or benign tumours) lesions of the optic tract or visual cortex can cause a contralateral homonymous hemianopsia. For example, a person who has a lesion of the right optic tract will no longer see objects on their left side. Similarly, a person who has a stroke to the right occipital lobe will have the same visual field defect, but there will be macular sparing.
A stroke on the entire right side of the brain, in addition to producing a homonymous hemianopsia, will also lead to the syndrome of Hemispatial neglect.
However, the symptom of homonymous hemianopsia isn’t necessarily of a lethal cause. For instance, it can constitute the aura phase of migraine.
Etymology
Etymology
Homonymous hemianopsia can be broken down as follows:
- Homonymous: same
- hemi: half of the visual field
- anopsia: blindness