Homonymous Hemianopsia

Overview

Homonymous hemianopsia (say: hoh-MON-ih-mus hem-ee-an-OP-see-uh) means you lose half of your side vision in both eyes, on the same side. It is not a problem with your eyes themselves. It happens when a part of the brain that handles sight is damaged. The word 'homonymous' means 'same side' and 'hemianopsia' means 'half vision'. So if you have it on the right side, you cannot see things on your right when you look straight ahead — with either eye. You can still see everything on your left. Most people describe it as the world suddenly becoming half as wide, or as if something is blocking one side of their view.

It is uncommon in the general population, but it is one of the more frequent vision problems seen after a stroke. Up to about one in three people who have a stroke affecting the back part of the brain may notice some loss of side vision.

It can affect anyone at any age, but it is most often seen in adults who have had a stroke, a head injury, or another brain condition. Children can have it too, for example after a head injury, an infection, or a tumour, and they may not be able to describe it clearly.

Symptoms

Common symptoms

• Not seeing things on one side — for example, people or doorways on your right or left seem to 'appear' suddenly.
• Bumping into objects, furniture, or door frames on the affected side.
• Missing words at the start or end of a line when reading.
• Difficulty finding things on a table, in a cupboard, or on a page.
• Being startled easily when someone approaches from the 'blind' side.
• Trouble judging distances or where things are, which can make driving or cycling unsafe.
• Sometimes the missing area is not completely blank — some people notice blurred or 'grey' patches at the edge.

Symptoms in children

• Bumping into things or tripping more often than expected for their age.
• Reading slowly, losing their place, or skipping lines.
• Turning their head or whole body to look at things, or tilting their head to one side.
• Struggling in busy places such as playgrounds or crowded rooms.
• Falling behind at school in reading or copying from the board.
• Young children may not be able to explain what is wrong — they may simply seem clumsy or 'not paying attention'.

Symptoms in older adults

• Falls and near-falls, especially in unfamiliar places or in poor light.
• Difficulty reading, watching television, or following a page or a recipe.
• Trouble with everyday tasks such as eating food on one side of the plate or finding items on a shelf.
• Problems when driving, such as not noticing a car or cyclist on one side.
• Increased risk of bumping into people in shops, queues, or at home.
• Sometimes anxiety about going out alone, which can lead to becoming more housebound.

Causes

Main causes

• Stroke — the most common cause, when blood flow to the back part of the brain is blocked or bleeds.
• Head injury or traumatic brain injury.
• Bleeding inside the brain (haemorrhage).
• A brain tumour or growth pressing on the visual pathway.
• Infection or abscess in the brain, or complications after brain surgery.
• Conditions that inflame or damage nerve fibres, such as multiple sclerosis or other demyelinating conditions.
• Sometimes a short-lived version can happen during a migraine, or during a seizure, and then clear.

Risk factors

• High blood pressure.
• Diabetes.
• High cholesterol.
• Smoking.
• An irregular heartbeat such as atrial fibrillation.
• Having had a stroke or a mini-stroke (TIA) before.
• Older age.
• A previous head injury.
• Heavy alcohol use and a very inactive lifestyle.

When to see a doctor

See a doctor urgently if:

• Any sudden change in your vision — treat it as an emergency until a doctor says otherwise.
• Side vision loss with weakness, numbness, speech trouble, or a facial droop.
• A new blind spot that comes and goes.
• Vision change after a bump to the head.
• A new severe headache with any change in vision.

Book a routine appointment if:

• You have noticed a patch of vision that has been missing for days or weeks.
• You keep bumping into things on one side or missing words when you read.
• You are finding it hard to drive, work, or get around safely.
• A family member or carer has noticed you not seeing things on one side.
• You had a stroke or head injury in the past and your vision has not been checked.

Diagnosis

A doctor will start by asking what you have noticed and when it began, and will check your blood pressure and general health. They will test your vision in each eye — often by asking you to look straight ahead while they move a finger or a target into different parts of your view. Because this condition comes from the brain rather than the eye, they will usually arrange a scan of your brain and a fuller eye and vision assessment.

Tests that may be done

• Visual field test (perimetry): you look straight ahead and press a button when you see lights or dots appear; this creates a map of what you can and cannot see.
• A full eye examination to rule out problems inside the eye itself.
• A neurological examination checking strength, sensation, reflexes, and coordination.
• CT or MRI scan of the brain to find the cause and its position.
• Blood tests, blood pressure checks, and sometimes a heart rhythm test (ECG) to look for stroke risk factors.
• In some cases, referral to a specialist eye doctor (ophthalmologist), a neurologist, or a stroke team.

What to expect at your appointment

The tests are quick and painless. The visual field test can feel tiring because it asks for steady concentration, and you may need to repeat it later. You will usually be told the results of your scan within days, and you should ask for a clear explanation of what was found and what happens next. It can help to bring someone with you, and to write down your questions in advance.

Treatment

There is no pill or procedure that simply switches the missing vision back on. Instead, treatment has two parts: finding and treating the underlying cause — for example, managing a stroke and its risk factors — and helping you make the most of the sight you have through vision rehabilitation. Many people improve steadily over the first three to six months, and some keep improving for longer.

Self-care at home

• Practise scanning: deliberately turn your head and eyes towards the 'blind' side every few seconds when walking, reading, or eating.
• Put things where you can see them — for example, place your cup, phone, and remote on your seeing side.
• Use a ruler, a card, or your finger under the line when reading, and use a bookmark to keep your place.
• Improve lighting at home and keep floors and stairs clear; remove loose rugs and trailing cables.
• Use labels, brightly coloured tape on edges of steps, or marked settings on appliances you use often.
• Ask about a driving assessment before getting back on the road — in many places you must tell the licensing authority about a visual field loss.
• Take breaks when you feel tired; side vision loss can make you work harder to take in the world, which is tiring.
• Ask your doctor or pharmacist to review your medicines and check your blood pressure regularly.

Medical treatments

Treatment focuses on the cause and on rehabilitation. If a stroke is the cause, your medical team will manage blood pressure, cholesterol, blood sugar, and heart rhythm, and may recommend blood-thinning or other medicines to lower the risk of another stroke — your doctor will explain what is right for you. For the vision itself, the main approach is vision rehabilitation: training in scanning and eye-movement strategies, occupational therapy for daily tasks, low-vision aids such as magnifiers and special lighting, and sometimes prisms or specially adapted glasses that shift images from the blind side into your seeing side. These aids do not restore lost vision, but many people find they make daily life noticeably easier. A physiotherapist, occupational therapist, or orthoptist (a specialist in eye movement and vision) can build a plan with you.

When is surgery considered?

Surgery is not used to restore the missing field of vision itself. It may be needed if the cause is something that can be operated on, such as a brain tumour or a collection of blood after a head injury. Some specialised eye-muscle surgery or prism implants are occasionally considered in expert centres, but this is not routine and only a specialist can say whether it might help in your case.

Living with this condition

Life with half a field of view means learning a new habit of looking around more deliberately. Most people find that with practice, scanning becomes automatic and they stop bumping into things as often. At home, keep furniture in familiar places, keep pathways clear, and put everyday items on your seeing side. When out and about, use crossings with signals, take your time, and consider using a cane or a companion in crowded places. Tell friends and family which side you cannot see, so they approach you from the other side and do not think you are ignoring them.

Lifestyle tips

• Keep a regular routine and get enough sleep — tiredness makes scanning harder.
• Stay socially active; groups, hobbies, and seeing people help mood and confidence.
• Avoid crowded, dimly lit places until you feel more confident, then build up gradually.
• Arrange a home safety check to reduce fall risks, especially on stairs and in the bathroom.
• Carry a card or note explaining your vision loss if it helps you feel more confident when out.
• Ask your employer or school about adjustments such as better lighting, larger print, or extra time for reading tasks.

Diet and exercise

Because stroke is the most common cause, looking after your heart and blood vessels matters. A balanced diet rich in vegetables, fruit, wholegrains, beans, and fish, and lower in salt, sugary drinks, and heavily processed food, supports healthy blood pressure. Regular activity — such as walking, swimming, or cycling on a stationary bike — helps too; aim for something most days if your doctor agrees. If you have balance problems, ask about physiotherapy or supervised exercise. Stopping smoking is one of the single biggest things you can do for your blood vessels, and your doctor or pharmacist can point you to support.

Mental health and emotional wellbeing

It is very common to feel shocked, frustrated, or low after losing part of your sight. You may feel grief for the way you used to see, worry about falls or driving, or feel anxious in busy places. These feelings are real and understandable, not a sign of weakness. Talking to your doctor, a counsellor, or a peer support group can genuinely help, and depression after stroke is common and treatable. If you ever have thoughts of harming yourself, please reach out for help right away — contact your local emergency number or a crisis support service in your area, and tell someone you trust.

Prevention

You cannot always prevent homonymous hemianopsia, especially when it follows a head injury or an unexpected brain condition. But because stroke is the most common cause, looking after your blood vessels lowers your risk: keep blood pressure, cholesterol, and blood sugar in a healthy range, do not smoke, stay active, and take any prescribed medicines as directed. If you have an irregular heartbeat, getting it treated is important.

Screening programmes

There is no routine screening test for this condition. Instead, anyone with stroke risk factors should have regular blood pressure and heart health checks, and anyone who notices a change in their side vision should be assessed promptly rather than waiting.

Complications

If left untreated

• Falls and injuries from not seeing obstacles on one side.
• Road accidents if driving continues without assessment.
• Reading and writing difficulties that affect work, study, or managing money.
• Bumping into people and objects, which can cause embarrassment and social withdrawal.
• Low mood, anxiety, and loss of confidence.
• If the underlying cause is not found, a stroke or other brain condition may go untreated and could worsen.

Long-term outlook

The outlook varies from person to person and depends on the cause and how much damage there is. Many people notice real improvement in the first few months, and almost everyone can learn practical strategies that make daily life safer and easier. Some people live with a permanent blind side but adjust so well that it becomes background rather than the centre of their lives. With the right rehabilitation, support, and attention to heart health, most people are able to return to a meaningful, active life.

Find support

External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.