FIXing vision problems in children with dyslexia is unlikely to have any effect on the condition, research shows.
Scientists found no evidence that visual deficiencies are linked to severe cases of "word blindness". The results call into question the value of common private treatments that can cost parents a small fortune.
Many experts had already cast doubt on the effectiveness of the therapies, which typically involve coloured lenses and overlays and eye exercises.
Lead researcher Dr Cathy Williams, from Bristol University, said: "We want to spread the word that if you look at a population of children with dyslexia, few of them have vision problems."