Children with dyslexia have difficulty in learning to read despite traditional instruction, at least average intelligence, and an adequate opportunity to learn. It is caused by an impairment in the brain's ability to translate images received from the eyes or ears into understandable language. It does not result from vision or hearing problems. It is not due to mental retardation, brain damage, or a lack of intelligence.
Dyslexia can go undetected in the early grades of schooling. The child can become frustrated by the difficulty in learning to read, and other problems can arise that disguise dyslexia. The child may show signs of depression and low self-esteem. Behavior problems at home as well as at school are frequently seen. The child may become unmotivated and develop a dislike for school. The child's success in school may be jeopardized if the problem remains untreated.
What causes dyslexia? What are the different types of dyslexia?
There are several types of dyslexia that can affect the child's ability to spell as well as read."Trauma dyslexia" usually occurs after some form of brain trauma or injury to the area of the brain that controls reading and writing. It is rarely seen in today's school-age population.
A second type of dyslexia is referred to as "primary dyslexia." This type of dyslexia is a dysfunction of, rather than damage to, the left side of the brain (cerebral cortex) and does not change with age. Individuals with this type are rarely able to read above a fourth-grade level and may struggle with reading, spelling, and writing as adults. Primary dyslexia is passed in family lines through their genes (hereditary). It is found more often in boys than in girls.
A third type of dyslexia is referred to as "secondary" or "developmental dyslexia" and is felt to be caused by hormonal development during the early stages of fetal development. Developmental dyslexia diminishes as the child matures. It is also more common in boys.
Dyslexia may affect several different functions. Visual dyslexia is characterized by number and letter reversals and the inability to write symbols in the correct sequence. Auditory dyslexia involves difficulty with sounds of letters or groups of letters. The sounds are perceived as jumbled or not heard correctly. "Dysgraphia" refers to the child's difficulty holding and controlling a pencil so that the correct markings can be made on the paper.
