Eyesight, or vision, is produced by the brain, which interprets signals detected by the eye. The eye collects and focuses signals formed when light falls on special cells at the back of the eye (retina) and the signals are sent along the visual pathway, starting with the optic nerve, to a special region at the back of the brain. Normal vision therefore depends on having a healthy eye, a clear visual pathway, and a normally structured brain. Even if the eyes look normal and are healthy inside, a vision problem may still be present.

At birth a baby does not see as clearly as an older child or adult. The world looks fuzzy or ‘out of focus’. Other aspects of vision also develop over time, such as the ability to actively look at something. As the baby grows and develops, the brain undergoes a process of maturation, which involves new brain cell connections being made and others being discarded. As the visual pathway matures vision becomes less fuzzy and other visual skills develop, for example the ability to look actively at things. Of course such maturation also affects other parts of the brain and supports the baby in developing many new skills, like the ability to control movement and to make sense of sound.

 How does vision help with development?

Vision is a very important sense in many areas of early childhood development. When a baby turns towards a sound made by an object that is out of sight, they begin to learn that the sound and the object that makes the sound are connected. If a baby can see an interesting toy that is out of reach, this can motivate the baby to reach out for it or to try to crawl towards it. Babies who have very limited vision may need help to learn these skills and do so more slowly.

 Can vision be helped to develop?

Much in the same way that physiotherapy is used to prepare muscles for learning to walk, you can stimulate a child’s vision using appropriate sized toys to help them practice and learn to see. If a child needs glasses you can encourage them to wear them – it can take years for them to get used to them as there isn’t always an instant improvement. But vision is more likely to improve if the brain has a clear picture rather than a fuzzy one to learn from.

 What about children with disabilities?

Children with disabilities also benefit from having good quality vision to support all these different developmental processes. We know that children with learning disabilities are 28 times more likely to have a serious sight problem than other children. If a child has a disability they are more likely to have an eye or brain problem, resulting in vision that isn't as developed as another child of the same age. If vision is less developed this could add further developmental difficulty for the child. It is therefore very important than any potential visual difficulties are identified so that appropriate treatment can be given. Some treatments can correct the problem itself and other treatments involve changing the ways a child is helped to learn. 

 Why is it particularly important to think about vision for children with disabilities?

Good quality vision is important for all children as it helps with all parts of learning and development. If a vision problem is present it can be easier to identify in a child who is developing normally, and treatment and advice can then be given. However, for a number of reasons, a vision problem may not be identified so promptly in a child with disability, meaning that opportunities for treatment or advice are not taken. This can lead to further unnecessary disadvantage for the child. Depending on the type of disability some children may use their vision for a wider range of purposes than a typically developing child. For example children who cannot speak may be able to communicate using pictures and if vision problems are not identified this could lead to inappropriate materials being used.

Although some vision problems cannot be fully corrected, it is important that they are known about so that appropriate adjustments can be made.  Sometimes vision problems can be overlooked if there is no obvious eye abnormality or at times when other health problems are causing concern.

It’s important to understand what size objects a child can see so you can choose appropriate toys or activities. It can help to know what size food a child can see to encourage independence. An understanding of each child’s vision in school is essential to know if children need larger size pictures to make choices. It’s important to know if a child sees better from one side than the other so they don’t miss out on learning through observation, or trip up if they can’t see in the lower part of their vision.

 How can vision be checked in children with disabilities?

A child does not need to be able to read - or even speak - for vision and eye health to be checked. The child’s responses to people, objects and pictures can be assessed by eye care specialists. They can check if a child needs glasses by using special lights and lenses without needing to cooperate with complicated tests. They can check if a child sees better from one side than the other, or if they find it difficult to see more than one object at a time. They can also check the health of the eye which is just as important as checking how good vision is.

 Who can help?

If a child has a Paediatrician talk to them about any concerns. They can then make an appropriate referral for the child to be seen by the most appropriate specialist. This may depend on the particular concern and on how services are organised locally. Sometimes some specialists from the eye clinic conduct assessments in the Child Development Centre or Paediatric Outpatients. Alternatively, a child may be referred directly to an Ophthalmologist at your local eye clinic. If the child does not have a Paediatrician the GP should be able to advise.

All children are entitled to a free NHS eye test at a community optician. However, not all optometrists will have experience in testing children who cannot perform standard tests so it is important to find the right place. Some opticians can also visit children in their own home if needed.  

Links between disability and vision

Children with learning disabilities are 28 times more likely to have serious sight problems with other children. This is because the causes of a learning disability can affect the way the eye and vision system has developed or functions. There are hundreds of syndromes and conditions which cause a child to have a learning disability, and many are likely to have an impact on vision.

 What vision problems do children with a learning disability have?

Children with a learning disability may have normal vision, require glasses or have a squint (turn in the eye) much the same as other children. Other children may be born with eye conditions or develop them through life, which may need treatment or may result in visual impairment. Some children with learning disabilities have problems using their vision in the same way as other children due to difficulties in the way the brain processes the information from the eye - this is called Cerebral Visual Impairment.

How does vision impact on learning?

80% of what happens around us is processed through our eyes so good vision is important for all aspects of learning, communication and social interaction. Knowing how well a child can see and how they use the vision  they have is important for planning how to present information, understand behaviour and to aid learning. Changes in behaviour and abilities could be an indication of a vision problem. Eye tests are the only way of knowing how a child sees so are essential for all children.

Much more information about eyes, vision, glasses and visual impairment can be found on SeeAbility's website.