A grandmother is fast becoming a household name with her books helping dyslexics to read and write.

Keda Cowling, 76, a retired teacher, spent 25 years devising the system and her two manuals, Toe by Toe and Striding Ahead, are now taught in 27 countries and more than 20,000 schools in the UK.

And the system is also helping prisoners learn to read. She also has a third book, Stareway to Spelling, coming out next week, so called because it is necessary for students to stare at the words.

Speaking at her home in Green Road, Baildon, Mrs Cowling said the system, first published in 1994, had spread by word of mouth. She employs three people to produce the books and her two sons, Frank and Kelsey, are also teachers and involved in the business. The system is even used in the Army in Germany and Cyprus and has enabled inmates at Wandsworth prison learn to read.

"Literate prisoners have acted as mentors helping others to read. I got a letter from one saying that the first thing he was going to do when he got out of jail was to teach his wife and three kids to read," Mrs Cowling said.

"It is really amazing how well the system is doing. It is used in Japan, Dubai, Hong Kong and nearly every school in Scotland."

She said Bradford's education system had additional problems with Asian youngsters facing a double handicap.

"I teach some dyslexic Asian children and it is really hard for them because the English language is so difficult. But they have done really well using this system and they can't believe their progress."

Mrs Cowling said she had not heard about dyslexia until she started teaching at Sandal First School in the 1960s.

A trip to New York led her to the Orton Society, named after a doctor in America who discovered dyslexia.

Back in Bradford she tutored groups of children after work in a bid to find a "cure" for the word blindness.

"I became obsessed, tried everything and then one day it just clicked."

She said that youngsters who are dyslexic cannot visualise words, but her system helps them to link sight and sound.

They are made to stare at words for some time, underline and then say the words. Jane Todd, of the Leeds and Bradford Dyslexia Association, said Mrs Cowling's books were a godsend.