An education professor has cast doubt on the scientific validity of the term 'dyslexia', saying experts cannot agree on what it is or how to treat it.
One in 10 Britons is thought to be dyslexic
Writing in the Times Educational Supplement, Julian Elliott said it was largely an "emotional construct".
The Durham University professor questions the scientific validity of the term 'dyslexia', saying diagnosis does not lead to particular treatment.
The British Dyslexia Association says the claims are inflammatory.
Professor Elliott, a psychologist, said his argument was based on "an exhaustive review of the research literature".
After 30 years in the field, he said, he had little confidence in his ability to diagnose dyslexia.
Professor Elliott told the BBC News website: "There is no consensus as to what it is and how to diagnose it. People describe all sorts of symptoms as dyslexia. And if you do diagnose it, it does not point to any intervention in particular.
"It's one of those terms that is like the Cheshire Cat - if it does exist, we don't know what to do about it."
He said, contrary to talk of 'miracle cures', there was no sound, widely-accepted body of scientific work that had shown that any particular teaching approach was more appropriate for 'dyslexic' children than for other poor readers".
Dyslexia is defined by BBC health expert Dr Rob Hicks as "a congenital and developmental condition that causes neurological anomalies in the brain.
"It includes a range of types of learning difficulties where a person of normal intelligence has persistent and significant problems with reading, writing, spelling and sometimes mathematics and musical notation."
Professor Elliott's claims have angered the British Dyslexia Association.
The charity's chief executive Professor Susan Tresman said: "I cannot accept that view, given the number of researchers into dyslexia that we work with. There were 900 delegates from 35 countries at our conference last year.
"There is as much a consensus view as in any area you would care to investigate.
"In excess of one million people download information from our website every month. Is he suggesting that they are all suffering from some kind of emotional delusion?"
Professor Tresman said people with dyslexia often had different symptoms - not just problems with words - and that Professor Elliott seemed to be viewing dyslexia just in terms of poor reading skills.
She said there was a series of well-recognised and highly sophisticated techniques used by psychologists to assess people for dyslexia.
In response, Professor Elliott said: "If you are going to include numbers and music the term is getting meaningless."
Government figures suggest that one in 10 Britons is dyslexic, with four out of 10 of those being severely so.
Students formally diagnosed as having dyslexia are given up to 25% extra time in GCSEs, A-levels and vocational assessments.