The problem was first described in 1896 by Dr. W. Pringle Morgan in
In 1887 by Rudolf Berlin used the term to refer to a case of a young boy who had a severe impairment in learning to read and write in spite of showing typical intellectual and physical abilities in all other respects.
Some early researchers believed dyslexia stemmed from a visual deficit. This notion has persisted in popular culture, where it is falsely believed that dyslexia equates to reading words backwards or upside-down.
A key early researcher in dyslexia was Samuel T. Orton. Orton coined the term strephosymbolia (meaning 'twisted signs') to describe his theory that individuals with dyslexia had difficulty associating the visual forms of words with their spoken forms. Orton observed that reading deficits in dyslexia did not seem to stem from strictly visual deficits. He also believed that dyslexics were disproprtionately left-handed, although this finding has been difficult to replicate.
In the 1970's, a new hypothesis, based in part on Orton's theories, emerged that dyslexia stems from a deficit in phonological processing or difficulty in recognizing that spoken words are formed by discrete phonemes (for example, that the word CAT comes from the sounds [k], [æ], and [t]). As a result, affected individuals have difficulty associating these sounds with the visual letters that make up written words. Key studies of the phonological deficit hypothesis include the finding that the strongest predictor of reading success in school age children is phonological awareness, and that phonological awareness instruction can improve reading scores in children with reading difficulties.
The Design versus Deficit debate — Thomas G. West, towards the end of the 20th century, suggested the theory that dyslexia may be design not deficit related, citing Galaburda and his own research. West suggests that many dyslexics belong to a much larger group of visual spatial thinkers who are wired for the big picture — designed to process information visually. It is only in a secondary state that dyslexics come to process information in a logical, sequential, language-based context. The uncomfortable reality may be that our education system indirectly attempts to screen out the Einstein gene, and thereby all our most original and gifted thinkers. West goes on to examine the difficult early experiences within education of five Nobel prize winners. or near-winners: Einstein, Edison, Marconi, Churchill and Faraday.
West's theory is echoed in the work of Ronald Dell Davis, author of The Gift of Dyslexia, who describes dyslexia as the outgrowth of a primarily picture-thinking mind. Davis posits that the symptoms associated with dyslexia arise from disorientation that results from confusion over language symbols. This view has also been supported indirectly by the research of by Linda Silverman, author of Upside Down Brilliance - the title reflects the counter-intuitive experiences of those who find the easy tasks difficult and hard tasks easy.
Echoes of this theory can be traced to the emerging discipline of NLP, the origin of VAK , now backed in the UK by the SEFD [Department for Education and Skills ]. Robin Williams of ABC, extended the theory to explain the paradox of bright under-achievers in his 0002 broadcast, The Einstein factor. The importance of a design-based theory is that design-based solutions are quite different from deficit solutions. A design solution suggests that literacy as a focus of the condition dyslexia must be considered a symptom and not the condition, that Professor Joe Elliott, the man most closely associated with 'The Dyslexia Myth documentary, may be right but for the wrong reasons. That IQ, as Elliott has argued, has nothing to do with literacy. This is where Elliott stops. A design theory argues that dyslexia as a condition is the result of a trade off and by identifying that trade off you can use strengths to offset the constellation of traits which constitute dyslexia , a condition related to a single root cause a difficulty with language [ dys - difficulty & lexia — language ] in all its forms: writing, reading, oral presentations and importantly memory. In other words, design not deficit.