Vision problems after stroke are the loss or change of sight that occurs when a stroke or transient ischemic attack (TIA) damages the occipital lobe of the brain or the visual pathways. Very often a person complains that they “can’t see on one side.” Such symptoms can appear suddenly and require immediate attention.
How a stroke affects vision
We see not only with our eyes but also with our brain: the image from the eye travels a long way to the occipital lobe, where the picture is formed. When a stroke cuts off the blood supply to these areas, the eyes may be completely healthy, yet the person cannot see part of the visual field. That is why it often happens that an ophthalmologist examines the eye and it is normal, while the real problem is in the brain. The disturbance may affect half of the visual field, sharpness, spatial orientation, or eye movements.
Causes and mechanism
- Ischemic stroke — a blockage of the vessel that supplies the occipital lobe or visual pathways.
- Hemorrhagic stroke — bleeding that compresses the brain’s visual structures.
- Transient ischemic attack (TIA) — a temporary disruption of blood flow, a “mini-stroke,” after which vision usually returns, but this is a serious warning sign.
- Damage to the visual tract or visual cortex — depending on the location of the injury, a different part of the visual field is lost.
- Disrupted function of brain areas that control eye movements and the coordinated vision of both eyes.
Symptoms
- Homonymous hemianopia — loss of the same half of the visual field in both eyes (for example, not seeing everything on the right).
- Quadrantanopia — loss of a quarter of the visual field (for example, the upper corner).
- Cortical blindness — significant or complete loss of vision while the eyes are perfectly healthy.
- Double vision (diplopia).
- Impaired eye movements, a “drifting” or uncontrolled gaze.
- Neglect of one half of space — the person seems not to notice objects or people on one side.
- Difficulty reading, bumping into objects, problems with orientation.
Why this is a neuro-ophthalmological condition
These disturbances lie at the border of neurology and ophthalmology, which is why they are managed by a neuro-ophthalmologist. They understand how the visual pathway is built from the eye to the brain and, by the pattern of visual field loss, can determine exactly which area was affected. A regular ophthalmologist checks the eye, while a neuro-ophthalmologist combines the eye examination with an assessment of the brain and nerves, giving a complete picture.
Diagnosis
- A detailed examination and history-taking, clarifying how and when the symptoms appeared.
- Visual field testing (perimetry) — to precisely determine which part of vision has been lost.
- Examination of the fundus and assessment of the optic nerve.
- Assessment of eye movements, pupil reactions, and the presence of double vision.
- Referral for an MRI or CT scan of the brain to confirm the stroke focus.
- Cooperation with a neurologist for a full evaluation and prevention of a repeat stroke.
Vision recovery and rehabilitation
After a stroke, vision may partly return on its own during the first weeks and months, but you should not wait without a diagnosis. The neuro-ophthalmologist assesses what deficit remains and helps you adapt to it: exercises for scanning space, special prisms for double vision, and advice on reading and moving safely. The role of the neuro-ophthalmologist after a stroke is not only to make a diagnosis but also to guide recovery, monitor progress, and coordinate treatment with the neurologist and rehabilitation specialists. Seeking help early improves the chances of a better outcome.
When to seek help urgently
If sight suddenly disappears on one side, your vision darkens, double vision appears, or half of the visual field drops out — and at the same time there is weakness in an arm or leg, a drooping face, speech difficulty, or severe dizziness — this may be a stroke. Do not wait and do not try to “sit it out”: call 103 or an ambulance immediately. Every minute saves brain cells and your vision.
German Eye Clinic, phone 0 800 507 670, the “Neuro-ophthalmologist consultation” service page.
