Dyslexia

I
INTRODUCTION
Dyslexia, the inability to learn to read fluently. No single definition of dyslexia is accepted by all reading specialists. In the United States, federal law governing special education classifies dyslexia as a “specific learning disability” or as a “specific reading disability.” The World Health Organization labels dyslexia a “specific reading disorder,” and other sources label it a “specific language disorder.” However, a central feature of all definitions is an unexpected and substantial difficulty in learning to read. The lack of a commonly accepted definition of dyslexia has caused some educators, physicians, and researchers to avoid using the term altogether.
Because there is no clear and widely held definition of the problem, estimates of the number of persons with dyslexia vary widely. Most researchers have suggested that dyslexia is rare, occurring in 1 to 2 percent of the world’s population. However, others contend that 10 to 20 percent of the population have dyslexia or display dyslexic characteristics. Those arguing for the higher incidence levels also suggest that dyslexia can appear in differing levels of intensity, affecting the reading achievement of some individuals more than others. Dyslexia is usually identified during childhood, but it continues to affect individuals throughout their lives.
II
CHARACTERISTICS
Before about 1970 most explanations of dyslexia held that the root of the problem lay in visual difficulties. For example, many experts believed that dyslexic children saw letters backward or in reverse order. Since then, however, much research has shown that children with dyslexia are no more prone to reverse letters while reading and writing than are other children.
Most dyslexia research now focuses on problems distinguishing the various sounds, or phonemes, that make up speech. Available evidence suggests that dyslexics have substantial difficulty decoding the phonological system of words—that is, they have problems breaking words into their various constituent sounds. For example, dyslexics may have difficulty breaking the spoken word hit into the three phonemes that correspond to the letters h, i, and t. Because they cannot segment hit into these three sounds, dyslexics often do not associate those sounds with the corresponding letters that would enable them to read the word. About 20 percent of all children experience some difficulty in distinguishing the individual sounds of spoken words. However, most of those children benefit from specialized instruction to treat reading problems early. Only 1 to 2 percent of children exhibit continuing reading difficulties after they receive such instruction.
III
INCIDENCE
Evidence suggests that dyslexia is more common in some families than others. Because of this, some researchers claim that there may be a genetic basis for dyslexia, but this has not been conclusively proved. Most studies have also reported that dyslexia affects significantly more boys than girls. However, a recent large-scale study reported that although schools identified more boys with reading problems than girls, test results showed severe reading difficulties in roughly equivalent numbers of both sexes.
IV
DIAGNOSIS
Common methods of diagnosing dyslexia vary widely, although most experts rule out other common sources of learning difficulty—such as lack of intelligence, absence from school, hearing or vision problems, and behavior disorders—before making a diagnosis of dyslexia. Many researchers have called for a shift in methods to identify dyslexia. Some argue that a diagnosis of dyslexia should be made only in children who continue to struggle with reading, even after having received high-quality, intensive tutorial instruction. This diagnostic method consists of two steps. First, experts assess the intensity and appropriateness of the instruction the child has received. If they find no evidence of an appropriate, intensive educational intervention to correct reading problems, then a diagnosis of dyslexia is premature. Second, experts assess the child’s ability to distinguish phonemes. Once again, a diagnosis of dyslexia would be premature if examiners identified difficulties in this area but found that the child had received no intervention to develop phonological processing skills.
Experts diagnose dyslexia only when reliable evidence shows that a child’s reading difficulties do not seem correctable through intensive, appropriate instruction. A child may not respond well in group instructional settings and may fall behind classmates in both reading acquisition and phonological processing skills. But these deficits alone would not warrant a diagnosis of dyslexia. Such a diagnosis is appropriate only if the deficits remain after the child receives intensive tutorial instruction to correct them.
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LIVING WITH DYSLEXIA
Many children experience some difficulties learning to read, write, and spell. With access to appropriate teaching, however, most of these children can and do become good readers. Effective instruction for dyslexics provides significant opportunity to read books of appropriate difficulty, meaningful writing activity, and guidance in developing useful strategies for decoding words and in establishing self-monitoring skills. However, few students with reading difficulties receive such instruction. Intensive tutorials often require one-to-one instruction, which most schools find too expensive to provide. A small number of private schools in the United States have well-researched and successful instructional programs for children with reading difficulties, but these serve relatively few students.
Even after receiving high-quality instruction, a small percentage of children fail to develop fluent reading abilities. Although these children are identified by most experts as dyslexic, even they can learn to read. Their reading often remains slower than their peers and the effort required for reading remains substantially greater. Nonetheless, many dyslexics not only graduate from high school and college but go on to excel in a wide variety of occupations.

Dyslexics get stuck at the starting gate because they can’t make the connection between the symbol and the sound.

D...........Disability to learn

Y...........Hundred years on {Understanding dyslexia}

S...........Spelling Disorder {Phonetics}

L..........Low school performance

E……… Early language impairment

X……….Genes on “x” chromosomes

I………..IQ above normal

A……….Attention deficit disorder