|The Simple English Wiktionary has a definition for: dyslexia.|
Dyslexia is a learning disability, a condition that makes it difficult to learn and understand things in the same way others do. It is a very common problem and has an effect on the way our brain understands words. The most common signs of dyslexia are reading and writing problems. Estimates are that in the United States between 5 and 9% of school children have dyslexia, though estimates go as high as 50%. Some cases of Dyslexia can be more damaging, commonly caused by a tumour in the brain which can result in lower cognitive function and in many cases, death. Dyslexia tumours can appear anywhere in the brain meaning that some dyslexia is different from others, ranging from problems with letters to paralysis and often death. There are a large array of dyslexia types, the rarest being contagious dyslexia. Approximately 1 in every 1,000,000,000 (billion) person suffers from this, which is located in the lower half of the cerebellum in all cases. This is critically damaging to motor skills such as movement and speech, often leading to major paralysis if the tumour grows. 
A person can have dyslexia even if they is very smart or educated. Recent studies show there are many small business owners that have dyslexia; between 35 and 50 percent of U.S. and British entrepreneurs are affected. Researchers think many dyslexic entrepreneurs are successful because they can delegate responsibilities (of writing letters) and still be good at speaking.
At the end of the 19th century, scientists did a lot of research about dyslexia and found some of the reasons that people are dyslexic. A professor who did research in the 1980s and 1990s looked at the brains of dyslexic people who had died. He found that some parts of the brain were not connected very well, and that this happened during the fourth month of pregnancy. This problem has a big effect on the left half of the brain. The newest research shows that three genes are the reason for dyslexia.
One thing that causes dyslexia is a problem with the central hearing nerve. This problem can not be found with a normal hearing test, so a special doctor has to do special tests to find it. It means that people with heavy dyslexia are sensitive to loud noise, may have problems speaking, and may not be able to concentrate. It may also cause problems with rhythm and melody of music.[needs to be explained]
In order to tell if a child has dyslexia, they have to be seen by a doctor. A child can be called dyslexic if they cannot read or write well and there is no other reason for the problem. Doctors are trying to create early tests to help find out whether a child has dyslexia before they are old enough to go to school. If this happens, a child can start to be treated very early, and they may have fewer problems at school. Many well-known people have dyslexia, including: Stephen Hawking, Jamie Oliver, Whoopi Goldberg, Ozzy Osbourne, Jay Leno, John de Lancie, Keira Knightley, Susan Hampshire, Orlando Bloom, Keanu Reeves, Richard Branson, Henry Winkler, Patrick Dempsey, Albert Einstein, and Tom Cruise. These people though continue to thrive with their work.
Children with dyslexia can be helped. One way teachers help dyslexic students is to break words into different sounds. The student must learn how to write the different sounds and create words. This helps with reading and writing. Some people think that dyslexic children can read and write better if they put pieces of colored paper on top of what they are reading.[source?]
- Shaywitz, Sally E. (August 2001). "The Neurobiology of Reading and Dyslexia". Focus on Basics. National Center for the Study of Adult Learning and Literacy. 5 (A). Archived from the original on 2008-03-28. Retrieved 2008-04-07. Unknown parameter
- Learning Disabilities: Multidisciplinary Research Centers, NIH Guide, Volume 23, Number 37, October 21, 1994, Full Text HD-95-005 ("LDRC longitudinal, epidemiological studies show that RD (dyslexia) affect at least 10 million children, or approximately 1 child in 5.")
- Brent Bowers (December 6, 2007). "Tracing Business Acumen to Dyslexia". New York Times. Cites a study by Julie Logan, professor of entrepreneurship at Cass Business School in London, among other literature.
- "History of Dyslexia | Dyslexia Awareness". www.dyslexia-aware.com. Retrieved 2017-05-23.
- Famous dyslexic people: Stephen Hawking