Uses and potential of EPUB ebooks for dyslexic people

In 2017 Luc Maumet, librarian and consultant in assisting technologies, studied for EDRLab what were the practices of French organizations specialized in dyslexia regarding the use of technology for helping dyslexic readers, and if standard usages and recommandations could be expressed in order to guide the work of EDRLab on open-source developments related to this kind of disability.

This first report was written in French and is freely available as:

This work was extended to Europe at large in 2018 and early 2019, the goal being to find other sources of experience in this field and confirm or update the conclusions drawn from the French experience.

This second report was written in French and English and is freely available in

On the software front, our first step was adding to the Readium toolkits and ot Thorium Reader the most important functionalities dys people expect from a reading system:

  1. Choose the font (with a font optimized for dys people, named Readable)
  2. Change the font size
  3. Change the spacing between characters
  4. Change the spacing between words
  5. Change the spacing between lines
  6. Change the spacing between paragraphs
  7. Change the size of margins
  8. Change the background and text colours (partial implementation)
  9. Activate text to speech, i.e. synthesis voice for continuous / on-demand reading

Thorium Reader can also read EPUB 3 ebooks with full audio (i.e. Media Overlays), and the same feature will soon (in 2023) be developed in the Readium Mobile toolkits.

Still, many useful features are missing in our software solution. We will develop these feature as soon as we have sufficient resources:

  1. Choose background and text colours (full implementation)
  2. Allow or prohibit hyphenation
  3. Change the number of visible lines
  4. Highlight punctuation by coloration
  5. Highlight syllables by coloration
  6. Apply alternative coloured frames for distinguishing lines
  7. Display a “reading rule” and read the text line by line.
  8. Support grammatical tagging in the text (e.g. the Mobidys Frog tagging).

The User Interface of Thorium Reader will be updated so that the user experience is totally fluid. A user will be able to easily select a set of features, and save them in named “profiles” for easy reuse.

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