The world’s biggest publishers dream of signing up bestselling authors such as Peter James, Lee Child, Karin Slaughter and Bernard Cornwell. Now a tiny Bristol publisher that specialises in books for dyslexic adults has secured a major deal to publish novellas by each of those authors.

Books on the Hill Press is the UK’s first dyslexia-only publisher. Its books use a different format, including a larger font and wider spacing between lines – adaptations that reduce processing demands, “unlocking the joy of reading a printed book” for dyslexic readers.

The publishing house is a one-man band headed by Dr Alistair Sims, 37, who also owns an independent bookshop in Clevedon near Bristol. Having been diagnosed as dyslexic aged nine, he was unable to read until he was 13. Thanks to a dyslexia unit at his school, he went on to study history and archaeology at university, completing a PhD.

Three years ago, he founded his publishing company because he struggled to find books specifically designed for adult readers with dyslexia.

It is estimated that about 10% of the UK population is dyslexic. While a range of books are published for dyslexic children, there is almost nothing available for anyone over the age of 14.

In his bookshop, Sims has certain shelves headed “quick read dyslexic friendly”. He said: “I’ve had people come into the shop and once they’ve looked at those books, they’ve said: ‘that’s something for me specifically, I can read this.’ A couple of people even cried. So it does make a difference to people’s lives.”

The crime writer Peter James recalled similar reactions when his novella, The Perfect Murder, was offered in a dyslexic-friendly version: “A middle-aged lady came up to me in tears and said that, for years, all she could read were children’s books and she was too embarrassed ever to be seen reading one in public. But now … she could enjoy my novellas and those of other authors and feel extremely proud to be seen as an adult reader.”

The historical novelist Bernard Cornwell said: “I hope my book with Books on the Hill will also bring people into reading more books.”

World Dyslexia Awareness Week begins on 7 October and Sims is campaigning to change attitudes within the book trade. He is calling for publishers to produce 1% of their fiction in dyslexia-friendly formatting and for booksellers to give such books the shelf-space they deserve.

He said: “People assume that, if a book is for dyslexic adults, then it’s simplified in plot and language, but it’s not. We’re not really changing the contents, we’re changing the formatting to make it easier to read.”

His book-covers look like novellas from any of the “big publishers”, he said, “because we want to make them look as good as possible so they wouldn’t seem out of place”.

Sims and his sister, who is also dyslexic, were among those who conducted extensive tests on print formats. Their texts are left-aligned rather than justified, which makes a huge difference to dyslexics, for example.

Noting that readers often complain about the small print size in traditional books, he said: “I have people who aren’t dyslexic look at our dyslexia books and say: ‘That’s easier for me as well,’ people who have had strokes and dementia.”

Sims believes that it is up to the big publishing houses to focus on major volumes, which are too expensive to produce for a tiny company like his. He said: “It’s on them to bring these dyslexic books to adults with our help and us being there. We’ll keep doing novellas and shorter stories. Also, some people are scared of big books.”

Speculating on why publishers have not seen this opportunity, he said: “Part of it is that a lot of people in publishing have no problems with reading.”

He expressed delight that Bloomsbury is now responding to this need. The Kite Runner by Khaled Hosseini is among dyslexia editions with “a large, more readable font” that will be launched on 31 October.

A Bloomsbury spokesperson said: “There are currently very few adult dyslexia-friendly books to choose from in the market … Dyslexic readers have the option of e-readers, but sometimes people just want to be able to read a physical copy of their favourite book.”