Henry Winkler on Dyslexia
Dyslexia Reading/Spelling disabilities
A neurological language-based disorder
"Dyslexia refers to a cluster of symptoms, which result in people having difficulties with specific language skills, particularly reading. Students...usually experience difficulties with other language skills such as spelling, writing, and pronouncing words. Dyslexia affects individuals throughout their lives..dyslexia can make it very difficult for a student to succeed academically in the typical instructional environment. From LD Online
The process of reading involves two processes: decoding the written word and comprehending the word. People with dyslexia usually have no difficulty with comprehension; they generally have adequate reasoning skills, vocabulary and syntax. The problem is that people with dyslexia cannot use these skills until the printed word has first been decoded and identified. New advances have documented that people with reading disabilities have a different pattern of brain activity than individuals without reading disabilities.
From ADA Learning Disability Fact Sheet