Cortical visual impairment

How do we see?

What we see is made up of 2 parts: our eyes and our brain.

Our eyes collect pieces of visual information from our surroundings and our brain puts them together to form an image or scene, a bit like putting pieces of a jigsaw together.

There are lots of different areas of our brain which are used to process what we see.

What is cortical or cerebral visual impairment?

Cortical or cerebral visual impairment (CVI) is where there is a problem with how the brain processes the information from our eyes. The eyes themselves may be healthy and working normally.

What causes a cortical visual impairment?

CVI can be caused by any condition or injury which changes structures within the brain. Some common examples of causes of a cortical visual impairment are:

• hypoxic brain injury (where the brain is starved of oxygen)
• prematurity
• meningitis
• epilepsy
• head trauma

We may not always know the exact cause of CVI. It is very common for children with CVI to have other health conditions or disabilities.

How does this affect the way my child sees?

Children with CVI will think what they see is normal as they have never seen any differently.

CVI is very variable. It can affect people differently and can even affect the same person in different ways on different days. You may find your child can see less well if they are very tired or not very well.

CVI can affect your child’s ability to:

• see clearly
• pick out details from a “busy” visual scene
• recognise objects
• see certain parts of a visual scene (visual field loss)

CVI is not a progressive condition which means your child’s vision should not get worse, unless they have other health conditions as well. Your orthoptist or ophthalmologist will be able to tell you more about your child’s condition and how well they can see.

What treatment is available?

Because CVI is caused by how the brain processes vision, there are no medical or surgical cures.

However, treatments and adaptations which can help to improve the level of vision your child does have and help them function in everyday life.

For example, your child may have a need for glasses as well as a CVI. Whilst glasses cannot give your child perfect vision, they can make sure the images the brain receives are as clear as possible. It is a myth that if someone is visually impaired that glasses are not helpful.

There are a wide range of low vision aids which can help someone with a CVI to see more easily. We can refer your child to our paediatric low vision service where a low vision specialist can teach your child to use a range of low vision aids.

Your child can be referred to a your local visual support service who can support your child at home, nursery, school and college to help them to access learning and reach their greatest potential.

Babies and young children can benefit from visual stimulation with lights and bright toys.

Small changes in your home can make things easier for your child to see and get around. For example, having brightly coloured everyday objects, such as a cup or a toothbrush, so that they stand out more easily from the background. Also, keeping the floor free of anything that your child could trip over if they did not see it.

Where can we get support?

There are lots of local and national support agencies that can offer you advice and support with your child’s diagnosis.

Make it easier to see is a really useful website about CVI and ways to help your child.

We will be happy to sign post you to other services as well.