It can be difficult to find out the cause of a sight problem. However, you need to know how much your child can see and how they use their sight.
Finding out about your child's eye condition
At the hospital or clinic
Your child's ophthalmologist (hospital consultant specialising in eye conditions) will work to find out how much your child can see and what causes the sight problem. Don't forget to ask questions or jot down notes during the consultation if you need to.
When you get a diagnosis, see our eye health section for more information about common eye conditions. For rarer diseases, see our page on rare eye conditions.
Is my child too young?
It's possible to do eye tests even with very young children, where all the child has to do is look at a picture. It's a good idea to ask around to find a child-friendly optometrist in your area.
In the classroom
Your child's sight problem could have a number of causes, so making an exact diagnosis might be difficult. In these cases, you still need to know how much your child can see (this is called functional vision).
If your child has some vision, teachers need to know how your child sees. They need to present information in the best way for your child to make use of any remaining vision.
The qualified teacher of visually impaired children (QTVI) may be able to do tests to check how your child uses their sight in everyday situations. These "functional vision assessments" aren't one-offs - they'll be done on an ongoing basis. See living and learning which gives you lots of information about school life and support for your child.
If your child has just been diagnosed, you may be wondering what to do next. See Coming to terms with your child's sight problem.
How you can help
You can play an important part in this process. Share what you know about how your child responds to visual stimuli (for instance lights and different colours). You could also mention if they seem to view things more easily on one side or the other.
What causes a sight problem?
Many sight problems are caused by something wrong with the eye. However, sometimes the brain doesn't translate images properly.
In some children, there is a problem with both the eye and the brain. In that case, getting glasses or contact lenses can still help your child to get the best image they can.
Technical terms
Here are some of the terms that ophthalmologists or teachers may use to describe what's causing the sight problem.
Functional vision
How your child uses their sight in everyday situations.
Ocular visual impairment
This means that sight problems are caused by one or more parts of the eyes not functioning properly.
Cortical or cerebral visual impairment (CVI)
In some children, there is nothing wrong with the eyes, but the brain doesn't process the images properly. This is called "cortical or cerebral visual impairment" or CVI. This is common for children who have multiple disabilities or complex needs.
Combinations
Some children may have a bit of both - a combination of CVI and ocular visual impairment. If that's the case, your child may need glasses or contact lenses to make sure they get the best image they can.
If your child only has CVI, then glasses or contact lenses probably won't be helpful. Get the professional's advice on other ways to help your child make the most of whatever sight they have.
More about eye tests and children
You can listen to an optometrist talking about how she does eye tests in our Eye Health Week podcast - listen or download it from our Podcasts page.