Dyslexia is a learning disorder that manifests itself primarily as a difficulty with reading and spelling. It is a reading disability due to a defect in the brain’s processing of graphic symbols, a learning disability that alters the way the brain processes written material. It is separate and distinct from reading difficulties resulting from other causes, such as a non-neurological deficiency with vision or hearing, or from poor or inadequate reading instruction. It is estimated that dyslexia affects between 5% to 17% of the U.S. population.
Although dyslexia is thought to be the result of a neurological difference, it is not an intellectual disability. Dyslexia is diagnosed in people of all levels of intelligence, average, above average, and highly gifted.
Two commonly held beliefs about dyslexia are that children with it are prone to seeing letters or words backward, and that the problem is linked to intelligence. Both beliefs are incorrect. The problem is a linguistic one, not a visual one, in dyslexia. And dyslexia in no way stems from any lack of intelligence. People with severe dyslexia can be brilliant. The effects of dyslexia, in fact, vary from person to person. The only shared trait among people with dyslexia is that they read at levels significantly lower than typical for people of their age. The treatment of dyslexia should be directed to the specific learning problems the person has. The usual course is to modify teaching methods and the educational environment to meet the specific needs of the individual with dyslexia.
The prognosis for people with dyslexia is mixed. The disability affects such a wide range of people, producing different symptoms and varying degrees of severity that predictions are hard to make. The prognosis is generally good, however, for individuals whose dyslexia is identified early, who have supportive family and friends and a strong self-image, and who are involved in a proper treatment program.