Researchers identify possible cause for dyslexia as well as a treatment

18 Oct 2017

A pair of scientists identified a discrepancy in the eyes of those with dyslexia. Image: photoJS/Shutterstock

A pair of French scientists have identified a tiny discrepancy in the eyes of people with dyslexia, potentially making it treatable.

As a learning difficulty, dyslexia affects approximately 700m people globally, hindering their ability to read, write and spell. However, there is now hope that a treatment could soon be on the cards.

According to AFP (via Medical Xpress), a pair of French scientists believe they might have found a physiological reason for dyslexia, located within minute light-receptor cells in the human eye.

In a paper published to the journal Proceedings of the Royal Society B, the University of Rennes researchers identified that in people with dyslexia, these cells are arranged in matching patterns, resulting in the creation of a mirror image. This is why they commonly mix up the letters ‘b’ and ‘d’, for example.

For a person who does not have dyslexia, these cells are arranged asymmetrically, which helps the brain to create a single image as the signals from one eye do not conflict with the other.

This, the pair claim, is the identifier of dyslexia and would allow for diagnosis to be a “relatively simple process”.

Lack of asymmetry

Other noticeable differences were spotted in the cones of our eyes – comprising red, blue and green variants – that help us identify colour. While the majority of these cones are found in the fovea, in the centre of the macula lutea, there exists a tiny hole where no blue cones exist.

Typically, people have holes of uneven shape in each of their eyes. However, in the eyes of someone with dyslexia, these holes are evenly round, resulting in neither eye being dominant.

“The lack of asymmetry might be the biological and anatomical basis of reading and spelling disabilities,” the scientists wrote in their paper.

“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.”

Possible treatment

Even more promising is the fact that their discovery of a tiny delay – a magnitude of just 10-thousandths of a second – in people with dyslexia could help develop a treatment to erase the problematic mirror image.

Using an LED lamp that flashes at a speed invisible to the naked eye, the mirror image can be cancelled out.

So far, tests with a small sample group have shown positive results, with the scientists claiming that one test subject described the treatment option as a “magic lamp”.

However, further testing will need to be done to test its true effectiveness.

Updated, 11.30am, 18 October 2017: This article was updated to amend an incorrect reference to the location of the fovea.

Colm Gorey was a senior journalist with Silicon Republic