New Study Ties Dyslexia To Vision Abnormalities

By Debra Viadero

A new study of dyslexia provides what researchers say is the first physiological and anatomical evidence that the reading disorder may be linked to the sense of vision.

The study, reported this month in the Proceedings of the National Academy of Sciences, challenges a previously held notion that the disorder is exclusively a malfunction of the way people understand language. Rather, the researchers hypothesize, dyslexia, which is characterized by difficulty in reading, may also stem from abnormalities in the "fast and slow" systems in the body for perceiving sight and, possibly, for perceiving sounds and sensations as well.

"The linguistic theory holds that [dyslexia is] a high-level cognitive defect," said Margaret S. Livingstone, the Harvard Medical School neurobiology professor who led the study. "But what we're saying is that that's secondary to the incorrect input a child may have been getting for...