Scientists in France have claimed they may have found a physiological cause for dyslexia which stems from the human eye.
The scientists reckon the problems stem from tiny little light receptors in the eyes of people with the condition.
In dyslexic eyes, the cells are arranged in matching patterns in both the eyes, which might well be the cause of confusion for the brain as it produces ‘mirror’ images.
In those without the condition, cells are arranged without this matching pattern, which apparently allows the different signals from the eyes to create one single image in the brain.
Guy Ropars, the study’s co-author, said in the Guardian:
Our observations lead us to believe that we indeed found a potential cause of dyslexia.
Even more interestingly, it makes diagnosis and treatment potentially much easier, with a doctor only needing to look into a prospective patient’s eyes.
…the discovery of a delay (of about 10 thousandths of a second) between the primary image and the mirror image in the opposing hemispheres of the brain, allowed us to develop a method to erase the mirror image that is so confusing for dyslexic people.
This would be done using an LED lamp.
As anyone who has had an eye test will know, everybody has one eye which works better than the other (like feet or hands). The two eyes create two separate images of the same thing and the brain selects one of the two.
Images are captured by the eye using a collection of rods and cones. These series of rods and cones are responsible for different things, with cones being responsible for colour.
The cones come in the classic variants of red, green and blue – they are situated in the fovea and they are minuscule.
In the study, Ropars and his co-author Albert le Floch found a major difference with the cones between the eyes of dyslexic and non-dyslexic people. This difference is related to a tiny part of the retina which has no cones at all.
Everybody has this part of the retina with an absence of cones, but in people without dyslexia, those cones are shaped differently in the dominant eye when compared to the non-dominant eye.
In the dominant eye, the cone was round, whereas the non-dominant one has an uneven shape. In dyslexic people the two holes in the eyes are the same shape.
This effectively means that those who have dyslexia do not have a dominant eye at all.
The study’s authors said:
The lack of asymmetry might be the biological and anatomical basis of reading and spelling disabilities…
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.
The scientific team tested their hypotheses using an LED lamp, which they flashed incredibly fast in one of the eyes of a dyslexic participant while they read. The light flashed so quickly the participant did not even register it.
The lamp ‘cancelled’ out one of the eyes signals while the participants were reading, and the results were so positive, they called it ‘magic’.
Obviously further tests will be required to verify this momentous discovery, but things look promising.