Dyslexia is often seen as a learning disability linked to the brain, but some research suggests it may also be related to an eye abnormality. This view challenges the idea that dyslexia is solely a question of the brain's processing of written information.
Understanding dyslexia
Dyslexia is a specific learning disability that affects reading, writing and spelling skills. People with dyslexia often have difficulty associating the sounds of language with the letters or groups of letters that represent them. This disorder is not related to intelligence or motivation but results from differences in language processing in the brain.
An anomaly in the eye: a potential new factor
Researchers have discovered that some forms of dyslexia may be linked to eye abnormalities, particularly in how the eyes process light signals. Several studies have highlighted differences in the fovea, the slight depression in the retina's center responsible for fine vision. In people with dyslexia, the fovea does not exhibit the same asymmetries between the eyes as it does in non-dyslexics, which disturbs visual perception.
Non-dyslexics have a natural foveal asymmetry: a difference in the distribution of light receptors (cones and rods) between the two eyes. This asymmetry enables the brain to distinguish more easily between the images each eye receives and choose one as a reference. Those with dyslexia, conversely, would have two symmetrical foveas, making it more difficult to merge the images and resulting in a “mirror image” that could complicate reading.
Consequences of reading and learning strategies
If this hypothesis is correct, it would explain why some dyslexic people see letters as if they were inverted or floating or why they may have difficulty following text from left to right. This challenges traditional approaches to dyslexia, which focus on auditory and phonological processing.
For affected children and adults, current solutions, such as visual training exercises, could be complemented by new approaches. Devices to adjust light or eye filters, such as coloured filter glasses, are being studied to improve the differentiation of images received by each eye.
What this means for the future
Although the idea of an ocular anomaly as a possible cause of dyslexia is not yet widely accepted, it opens up interesting prospects for new forms of management. By combining this approach with conventional teaching strategies, better support for dyslexic people may be possible.
Dyslexia remains a complex area in which many factors, including cognitive, neurological, and now potentially ocular aspects, play a role. Further research will help us better understand the multiple facets of this disorder and diversify the options for improving learning and quality of life for those affected.
In conclusion, the idea of an eye anomaly as a contributing factor to dyslexia is intriguing and deserves further attention. It could offer a glimmer of hope to those struggling daily with this disorder and broaden the horizons of dyslexia intervention strategies.
