The exact cause of learning disabilities is unclear. They appear to be due to disorders or developmental delays involving the brain. Inherited factors may play a part. The exact neurochemical difficulties within the brain are not known and the subject of ongoing, scientific research.
Although poor vision, jerky eye movements, misaligned or crossed eyes, and hand-coordination have at times been claimed to be the cause of letter reversals or reading disabilities, there is little to no scientific evidence to support this belief.
Stated simply, the eyes function as a camera. After the eyes “take the picture,” it is sent to the brain by the optic nerves. The eyes do not comprehend reading any more than a camera interprets a picture. Until the picture from the camera is developed, it has no meaning. Similarly, until the brain interprets or “perceives” the pictures sent by the eyes, there is no understanding. With processing disorders involving what is heard, think of the ears in a similar fashion.
This perceptive ability by the brain is the key to the child’s ability to read or hear and understand what is presented in the learning environment. . Perception is quite different from vision and sight. It is the ability of the brain to recognize, use, and interpret visual images by relating them to previous experiences. In the past, reading problems have been blamed on the eyes though children with a learning disability have no greater incidence of eye problems than the rest of the population.
Some learning disorders, such as dysgraphia and dyscalculia, on the other hand, are primarily disorders within the brain leading to an inability to process internally and coherently and correctly present materials to the environment, rather than involving perceptual difficulties.