Cerebral Visual Impairment

What is cerebral visual impairment?

Cerebral visual impairment is the name for problems with vision that stem from the brain rather than the eye.

Our eyes turn light from the world around us into electrical signals. The signals are sent along connections between nerve cells (‘the white matter’) to many different areas in the brain (the cerebrum).

The visual brain uses these signals to piece together different aspects of what we see. It works out what an object is, where it is, whether it’s moving or whether we’ve seen it before.

Damage to the visual brain and its connections (the visual pathway) leads to different problems depending on where it is. For example, someone with cerebral visual impairment might not be able to see anything in the top left of the view ahead, or might have trouble recognising faces.

What causes cerebral visual impairment?

There are several causes of cerebral visual impairment. It may be part of a wider neurological condition that affects thinking, movement, or other senses such as hearing or touch, and may happen in people with epilepsy.

Lack of oxygen to the brain in premature or full-term babies can damage white matter. Infection, such as meningitis or encephalitis, can also damage brain tissue, as can head injury.

Cerebral visual impairment may also follow brain surgery, for example to cure epilepsy or remove brain tumours, if part of the visual pathway is damaged in the process.

What are the signs and symptoms of cerebral vision impairment?

Common signs and symptoms of cerebral visual impairment include

• being sensitive to light (photophobia) or staring into light (light-gazing)
• not looking into people’s eyes (poor ‘social gaze’)
• never fixing on objects for long
• trouble with smooth eye movements, e.g. to follow moving objects
• not doing well on sight test charts (poor visual acuity)
• only seeing some parts of the world ahead (visual field loss)
• being clumsy with objects, e.g. reaching past them, knocking them over, bumping into things
• getting tired doing tasks that need vision
• seeing moving objects better than still (static) ones
• seeing colour better than black and white
• trouble recognising familiar people or places
• trouble picking out one item when lots of items are in view
• finding it harder to see when it’s noisy

How is cerebral visual impairment diagnosed?

It’s important to diagnose cerebral visual impairment as early as possible to help children get the support they need to develop as normally as possible. Improving brain imaging and tests for different visual problems will help speed up diagnosis and make it easier to recognise the symptoms.

What are the treatments for cerebral visual impairment?

There is no treatment or cure for most types of cerebral visual impairment. However, several things may help people to see better.

If glasses or contact lenses are needed (for example to correct short-sightedness), they will help the light that gets turned into electrical signals to be as clear and focused as possible. This is especially important for children as the brain grows and develops.

What can help cerebral visual impairment?

Large, widely spaced print, using a computer and using a ‘letterbox’ to see one word at a time can make reading easier. Using other senses, such as sound and touch, and removing distractions from the environment may also help.

What research is there into cerebral visual impairment?

Cerebral visual impairment research is focused on prevention and on improving diagnosis. It is not possible to repair brain damage to the visual pathway with drugs or surgery, but preventing some of the causes, such as infection or lack of oxygen, can mean that damage is avoided in the first place.

See our research projects