"Our observations lead us to believe that we indeed found a potential cause of dyslexia", Professor Guy Ropars, the study's co-author told the Agence France Presse (AFP) news agency.
Scientists have found dyslexics have an unusual pattern of cells in their eyes that makes letters hard to read.
They also found a way to treat the problem, using an LED lamp, but it is not known if this will work for all sufferers, who include people such as Sir Jackie Stewart, Tom Cruise, Orlando Bloom, Keira Knightly, Jamie Oliver, Richard Branson and Johnny Halliday.
"The asymmetry is necessary to eliminate the mirror image, that prevents a normal reading if it persists as in dyslexia", he continued.
They discovered differences in the shape of spots located in the red, blue and green cones of the eye, which are responsible for color.
There is a delay of a 10 thousandth of a second between the primary image and the mirror image in opposing hemispheres in the brain.
According to the new study, in non-dyslexic people, these two spots are shaped differently; one is round, and the other a less even shape. The dominant eye has more receptors than the other, and sends a better image to the brain.
As for the dyslexic, the blue cones were symmetrical.
"The lack of asymmetry might be the biological and anatomical basis of reading and spelling disabilities", the authors wrote. "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", researchers said in a statement.
In dyslexics, both eyes have a circular pattern of cones, which means each eye battles for dominance, causing confusion in the brain. The brain accepted information from the dominant eye and disregarded that from the other. Although this learning disability can be easily managed, it may impact the life and learning of those with it.
Ophthalmologists will be able to diagnose the problem by looking into people's eyes and treatment may come in the form of special spectacles that cancel or block out the confusing signals. The test comes in three parts. Part three involves assessing whether encoding is eidetic or phonetic.