Till sometime back, individuals who had problems in grammar, reading, pronunciation, spelling, numbers were labeled lazy, slow learners or stupid. But, as the awareness about dyslexia characteristics has grown educators have realized that what they labeled as plain laziness, stupidity or slow learning is in fact due to learning disability. What does cause dyslexia? Plenty of medical research has been carried out and one of the biological dyslexia causes is the discrepancy in the magnocellular pathway of the brain or to put it simply, the optical processing path of the brain which is responsible for the production of brightness and motion. The lack of development in the parvocellular pathway which is responsible for colors and details may also be the biological reason behind dyslexia. A dyslexia test is very helpful in evaluating this problem and can help in defining whether this is where the learning impairment begins.

Many medical dyslexia articles also put the blame squarely on the deficiency of sensory coordination. People with dyslexia have a tough time in grasping sensory information which leads to their learning problems. The communication between the left and the right hemispheres of the brain is also poor and is believed to be causing this learning handicap. Once the various biological causes have been identified, dyslexic diagnosis will become much easier and the correct treatment can be started. So, dyslexic people need not berate themselves about being less smart than their peers; there may be biological reasons for their having certain learning difficulties.