The presumed link between vision problems and dyslexia is not supported by evidence, scientists have found
In the first study of its kind, scientists found no evidence that visual deficiencies are linked to severe cases of a condition sometimes known as "word blindness".
The research, published in the journal Pediatrics, calls into question certain common, private treatments whose costs can run into the thousands
Experts had already cast doubt on the effectiveness of the therapies, which typically involve the use of coloured lenses and overlays and eye exercises.
Lead author Dr Cathy Williams, from the University of Bristol, said: "We want to spread the word that if you look at a whole population of children with dyslexia, very few of them have vision problems.
"Some practitioners feel that vision impairments may be associated with dyslexia and should be treated. However, our study results show that the majority of dyslexic children have entirely normal vision on the tests we used."