Call for more Irlen Syndrome specialists in schools
Calls have been made for more vision specialists in schools across Wales, to ensure children with Irlen Syndrome receive a diagnosis.
Irlen UK said children were "being turned off education" because they were not aware they have the condition.
It affects the brain's ability to process visual information and can cause difficulty reading and writing.
Education Secretary Kirsty Williams said all pupils have an eye test by an optician when starting school.
However the condition is usually only identified through further tests.
Irlen UK said about 15% of people are thought to be affected by the syndrome.
People with the condition often find coloured overlays, either as glasses or lenses, help their vision.
But Irlen is not yet recognised or properly defined as a medical condition and the NHS in Wales does not fund assessments although tests are available from some high street opticians.
People with the disorder said they believed earlier intervention would have helped them.
Jennifer Owen, 28, from Merthyr Tydfil, found out she had the disorder in 2012 and now campaigns to raise awareness of the condition.
She did not gain any GCSEs and believes she would have done better if she had been screened in school.
"I couldn't read or write. My teachers thought I wasn't trying," she said. "There's a risk of children falling through the net."
Sarah Chambers, 45, from Cardiff, who has Irlen, said her daughter has recently been diagnosed aged eight.
She claimed teachers were not trained to properly identify when a child might have it, meaning they "go through school thinking they're failing".
What is Irlen Syndrome?
- A perceptual processing disorder- it is not an optical problem
- Symptoms include distortion of words, brightness and glare, effects on reading and writing, poor motivation
- People with the condition may also have ADHD, dyslexia and behavioural problems
- Coloured overlays can be worn to filter out specific wavelengths of light
Stephanie Jamison, Irlen director and diagnostician for south Wales and south west England said while funding for testing is available at university level, she said children may struggle to reach further education without an earlier diagnosis.
"They could have been turned off education because studying is so difficult for them," she said.
"Sometimes children are being excluded from school for it.
"Irlen isn't just a reading problem, it's a light sensitivity issue which can have a wider impact like poor concentration and fatigue."
Ms Williams said: "The Welsh Government recognises the importance of putting in place early and effective interventions to ensure that any learner experiencing difficulties with their vision is not adversely affected in terms of their educational outcomes."