Dyslexia is generally assumed to involve "phonological processing" or the ability to attach sounds to letters and words. Children with dyslexia have difficulty with phonological processing; there is a disconnect between the brain's seeing a word (visual) and recognizing its sound (verbal). The Orton-Gillingham method and others like it stress multisensory methods of stimulating the brain and working around this disconnect, improving phonological processing phoneme-by-phoneme.
But some researchers believe that dyslexia is also related to a "processing speed deficit" or an inability to quickly analyze letter and word patterns. Some children with dyslexia may recognize phonemes and still be unable to read efficiently because the connection between sight and sound is so slow. This possibility has led some researchers to develop video "games" specifically designed to increase a child's processing speed. The American Pyschological Society has an interesting online article on this research.
info [at] windyrow.org (Windy Row Learning Center) understands that each child's dyslexia and each child's experience with reading is different. We move forward one step at a time, to make sure that a child is making progress and that we are concentrating on the areas where the child is struggling the most.