A brand new study out of France's Université de Rennes is changing how doctors think about dyslexia. This revolutionary report suggests that dyslexia may have more to do with a malformation in the eyes than in the brain.
Study authors examined the eyes of 30 dyslexia patients and 30 people without the disorder. They immediately noticed that dyslexics had differently shaped spots in the area of the eye that governs pigment colour.
Specifically, researchers found that most non-dyslexics had one large spot in one eye and a thinner spot in the other eye where blue cones are stored. By contrast, dyslexics had two round spots in the same places in both eyes. This obviously shows that dyslexics are more prone to have two equally dominant eyes.
For healthy vision, humans actually need one eye to be stronger than another. This helps the brain better differentiate characters as we read. Oftentimes the eye that's more dominant is the same as our dominant hand.
The French scientists believe the spots in dyslexia patients' eyes make it more difficult for their brains to differentiate similarly formed letters.
The head authors on this study were Drs. Albert le Floch and Guy Ropars, both of whom teach at Université de Rennes. In their published report, the authors hypothesized, "For dyslexic students, their two eyes are equivalent and their brain has to successively rely on the two slightly different versions of a given visual scene."
John Stein, a neuroscientist at the University of Oxford, told reporters this new study made a great deal of sense from a neurological point of view. He explained that the human brain needs only one dominant eye to form better neural connections between the left and right hemispheres.
Although Stein believes this research is promising, he cautions against over-exuberance. He reminded journalists that dyslexia is an extremely complicated disease. While differences in eye dominance might play a role in some patients' disorders, there's no "one size fits all" solution.
A few eye doctors are interested in developing surgical or drug treatments to rebalance dyslexia patients' eyes. There's no word yet whether researchers at Université de Rennes will explore possible treatments in the near future.
Dyslexia is an inherited disorder that affects roughly 10 percent of the UK's population. Common symptoms of dyslexia in children include difficulty reading, speech impediments, trouble memorizing words, and frequent headaches. The most common treatment strategies for dyslexia include cognitive behavioral therapy and special education programs.
Anyone can read this full study in the October 18th edition of Proceedings of the Royal Society B. This study is called, "Left–right asymmetry of the Maxwell spot centroids in adults without and with dyslexia."