New research shows dyslexia is completely unrelated to problems with vision, even though children with the condition are generally given eye exams and treatments.

The study found the majority of 5,822 children with dyslexia had perfect vision, the University of Bristol reported. In the past, studies on the subject only included small numbers of children, making this recent study the first of its kind. The researchers found 84 percent of the dyslexic children combined information from each eye perfectly; 3-D vision was also close to perfect in 83 percent of the children with dyslexia.

"These population-based results give the 'bigger picture' and show us that vision problems are rare in dyslexic children. The few vision impairments we did see in the dyslexic children also occurred in their non-dyslexic classmates," said Cathy Williams, a paediatric ophthalmologist and the study's lead author. "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."

The researchers urge parents of dyslexic children to ask what visual impairment is actually being treated and what evidence there is that the treatments will improve their child's condition.

"Our findings may reassure families that their child's sight is very unlikely to be affecting their reading ability (assuming the need for glasses has been ruled out) and so they can pursue other options for supporting their child," said Alexandra Creavin, one of the co-authors from Bristol's School of Social and Community Medicine. "Fortunately there are treatments and training [programs] to help children with dyslexia that do have a good evidence base, including training in phonics (speech sounds). 

The findings were published in a recent edition of the journal of the American Academy of Pediatrics (AAP).