Dyslexia is about having problems with a culture's visual notation of speech. The form of the notation varies according to the writing system adopted and developed by each culture. Much of the early dyslexia research was based in cultures that adopted a Latin Alphabetic writing systems.
Dyslexia and language orthography
The Orthography of language has its origins in the Writing Systems developed or adopted by each culture, which varies around the world. There are also orthological differences within each of the main writing systems.
History of developmental dyslexia
Dyslexia was first identified by Oswald Berkhan in 1881, and the term 'dyslexia' later coined in 1887 by Rudolf Berlin, an ophthalmologist practicing in Stuttgart, Germany.  The history of dyslexia has been the history of dyslexia research.
Research and theories
The theories should not be seen as competing, but viewed as theories trying to explain the underlying causes of a similar set of symptoms from a variety of research perspectives and background.
The medical research of dyslexia began with the examination of post autopsy of brains from people who had dyslexia, which led to the present day genetic research regarding dyslexia. The parallel evolution of both the theories of dyslexia and the brain scan technology inspired the current interest in researching the cognitive neurological causes of dyslexia.
In recent years there has been significant debate on the categorization of dyslexia. In particular, Elliot and Gibbs argue that "attempts to distinguish between categories of 'dyslexia' and 'poor reader' or 'reading disabled' are scientifically unsupportable, arbitrary and thus potentially discriminatory".
While acknowledging that reading disability is a valid scientific curiosity, and that "seeking greater understanding of the relationship between visual symbols and spoken language is crucial" and that while there was "potential of genetics and neuroscience for guiding assessment and educational practice at some stage in the future", they conclude that "there is a mistaken belief that current knowledge in these fields is sufficient to justify a category of dyslexia as a subset of those who encounter reading difficulties".
The Dyslexia Myth is a documentary that first aired in September 2005 as part of the Dispatches series produced by British broadcaster Channel 4. Focusing only on the reading difficulties that people with dyslexia encounter the documentary says that myths and misconceptions surround dyslexia. It argues that the common understanding of dyslexia is not only false but makes it more difficult to provide the reading help that hundreds of thousands of children desperately need. Drawing on years of intensive academic research on both sides of the Atlantic, it challenged the existence of dyslexia as a separate condition, and highlighted the many different forms of reading styles.
Julian Elliot, an educational psychologist at Durham University in the United Kingdom, disputes the characterization of dyslexia as a medical condition, and believes it should be treated simply as a reading difficulty. According to Elliot, "Parents don’t want their child to be considered lazy, thick or stupid. If they get called this medically diagnosed term, dyslexic, then it is a signal to all that it’s not to do with intelligence.” Elliot believes that children of all levels of intelligence may struggle with learning to read, and that all can be helped by educational strategies appropriate to their needs. He feels that resources are wasted on diagnosis and testing, and favors early intervention programs for all struggling readers. More recently Julian Elliot has also made reference to the 28 Definitions of Dyslexia which were documented in the Appendices of the National Research and Development Centre for Adult Literacy and Numeracy report on Developmental dyslexia in adults: a research review by Michael Rice with Greg Brooks May 2004. 
John Everatt of the University of Surrey 2007, has suggested that:-
- dyslexic students can be distinguished from other children with low reading achievement by testing geared to assessing their strengths as well as weaknesses
- dyslexic children tend to score significantly better than other children, including non-impaired children, on tests of creativity, spatial memory, and spatial reasoning
- dyslexic children also perform better than other reading-impaired children on tests of vocabulary and listening comprehension
- dyslexic children may be better served by educational intervention which includes strategies geared to their unique strengths in addition to skill remediation
and thus recommends more comprehensive evaluation and targeted interventions.
- List of writing systems
- List of languages by writing system
- Writing system
- Written language
- Medium of instruction
- English orthography
- BERKHAN O. Neur. Zent 28 1917
- Wagner, Rudolph (January 1973). "Rudolf Berlin: Originator of the term dyslexia". Annals of Dyslexia. 23 (1): 57–63. doi:10.1007/BF02653841. Retrieved 2009-05-12.
- "Uber Dyslexie". Archiv für Psychiatrie. 15: 276–278.
- Elliott, Julian G.; Gibbs, Simon (2008). "Does Dyslexia Exist?". Journal of Philosophy of Education. 42 (3–4): 475–491. doi:10.1111/j.1467-9752.2008.00653.x. Retrieved 2009-06-22.
- "The Dyslexia Myth". Dispatches. Channel 4.
- Blair, Alexandra (2007-05-28). "Dyslexia 'is used by parents as excuse for slow children". London: Times Newspapers Ltd(United Kingdom). Retrieved 2007-05-29.
- Moorhead, Joanna (2005-09-07). "Is dyslexia just a myth?". London: Guardian Unlimited. Retrieved 2007-05-29.
- Rice, Michael; Brooks, Greg (2004-05-01). "Developmental dyslexia in adults: a research review". National Research and Development Centre for Adult Literacy and Numeracy. pp. *133–147. Archived from the original on 2007-10-20. Retrieved 2009-05-13.
- Clark, Laura (2009-04-07). "Dyslexic children simply struggle to read': Expert claims tens of thousands are being falsely diagnosed". The Daily Mail. Associated Newspapers Ltd. Retrieved 2009-05-14.
- Everatt, John; Weeks, Sally; Brooks, Peter (23 July 2007). "Profiles of Strengths and Weaknesses in Dyslexia and Other Learning Difficulties". Dyslexia. John Wiley & Sons. 14 (1): 16–41. doi:10.1002/dys.342. PMID 17659648. Retrieved 2007-07-26.