Dyslexia is most often associated with reading and writing however it goes much deeper then that. People that have it severely are affected in all parts of life. It is not a reading disorder as much as it is a disorder of the way the neurons fire in the brain. Some neurons may be "talking" to one side of the brain but the other side will not "talk" back. This can affect them in all aspects of life but since many letters and words look similar this affects them the most. The most common thing in dyslexia is mistaking a b,p,q due to the brain not being able arch the neurons to talk to each other. These people many time will have a talent for math because they are better then most at concentrating for one side of the brain. So you see its not something you "develop" it is something you are born with. By the way dyslexia is not a bad thing. Some people who have it are(were) Albert Einstein, George Burns, Hans Christian Andersen and Alexander Graham Bell.