Dyslexia, Fonts & Open Source



July 27, 2011

At CSUN15, Anne Comfort of Mount Allison University presented an interesting study - Can a font improve reading? - of over 200 full time students with dyslexia. In this study they were not able to demonstrate that changing the font helps readability for this population. There's a great summary of this in Adrian Roselli blog post after CSUN.

It's important to note that there is considerable controversy around whether or not fonts can provide any benefit for people with dyslexia. In 6 Surprising Bad Practices That Hurt Dyslexic Users there is a list of some basic things that can be done which are more likely to improve readability. I can see means which a Drupal module could be built to strip out unneeded spaces which impact the river effect, eliminate double spacing after periods, allow for an adjustable background, warn about long unbroken paragraphs. With many WYSIWYG editors it is possible to remove or filter out justified text & italics already. Choosing a serif font for the body of your message is clear, but inside that there is a huge variety of options.

A recommended book Reading in the Brain: The Science and Evolution of a Human Invention from @lizditz who has been having a very good discussion with me on & @Diane_Duff Twitter.

Abelardo Gonzalez created a font licensed under the creative commons which he made available via Dafont.

I've been trying to learn more about how to support people with dyslexia and so have been reading up about good font options. There are a few which have been recognized as being better than others to help people distinguish the difference between b's & d's. The most interesting work I've seen on this is from Christian Boer of Studiostudio who created the font Dyslexie. The focus of most fonts geared for dyslexic people has been print and sadly there still aren't any strong, reliable options for the web.


Historically, any interesting fonts would have needed to be embedded within images or flash files because there were less than 10 fonts that you could rely on your users having installed on their computer. Using Flash or images to convey text always complicates things for accessibility, plus maintaining a library of old image files was also a pain. This has changed with modern web browsers, and there are now a number of ways to introduce more fonts to the web.

Introducing Web Fonts

Because of this, there has been a great deal of interest about web fonts. Google is jumping in full force with Google Web Fonts & the Google Font API. CSS3, the latest version of the Cascading Style Sheet engine, is offering a way to embed fonts directly with CSS. There are a growing list of fonts which are published with open licenses and which can be freely used on the web. There also approaches like sIFR which provide solutions for those who want to support older browsers.

So with this interest I was surprised that I wasn't able to find a free web font I could use to help make my site easier to read for people with dyslexia. There are a few that are made available at a low charge like Gill Dyslexic (No longer available). There's a print house that has a neat font, but apparently they made an agreement with Microsoft to restrict it's general distribution.

Free Fonts

There are some great web fonts available through Font Squirrel that can be used to enhance the look of your site, one of which was produced by the RNIB & released under the GPL License. The Tiresias family of fonts were designed under the direction of Dr John Gill at the RNIB Scientific Research Unit and Tiresias Infofont is available through Font Squirrel as a @font-face kit making it quite simple to implement.

Now the RNIB developed this font for low vision users, but they didn't develop it for people with dyslexia. Many of the letters could be fairly easily confused by people with dyslexia (and it wasn't designed for this purpose). However, since it's released under the GPL license, it is free for people to use and modify. There are also some great open source tools to modify fonts including Font Forge which allows people to manipulate the scalar vector graphics which make up True Type Fonts(TTF).

Creating More Fonts for Dyslexia

Because there are now several fonts that are available under a GPL license, I decided to extend the Tiresias font to have an example which has many of the principals developed for Dyslexie. Now this is more of a demonstration piece than anything, but I wanted to show as an example that we can provide more space for personalized fonts. Looking at the studies behind Dyslexie it looks like it hasn't undergone a very large study (one Master's thesis in the Journal of Integrative Neuroscience), but the initial results seem promising. There definitely need to be larger & more conclusive studies about fonts & dyslexia.

Perhaps there are other solutions that will work better for different people, and when there are tools as simple as Font Forge out there, why not encourage people to experiment to find out what they find the easiest to read. There is an interesting conversation in Hacker News proposing a number of variations & considerations. This is a much more interesting exchange looking at possibilities for this approach.

There are a number of changes that have been proposed for people with dyslexia, and unfortunately they aren't easily codified so that they are easy to test against and improve. Everything from removing double spacing after periods to reducing the contrast between the text & background has been suggested. Character misreading is only one of many types of dyslexia. Perhaps there are other ways to help visitors who have problems seeing the letters out of place. In print we're usually limited to black/white, but this isn't the case with web fonts. With the help of JavaScript we can begin to add color or other visual queues to highlight combinations which are problems for some people. We can provide higher levels of personalization on the web to ensure that people are able to get more out of the content that they are reading.

I don't feel like I have a particularly stunning font at the moment (although this is just the first draft after 3-4hrs of work). What I want to illustrate is that individuals how the power to customize fonts to make it easier for themselves and people who struggle with dyslexia. By collaborating with others however, we can produce fonts that make it easier for everyone. The font used in this page is available for download and is licensed under the GPL as it is a derivative of the RNIB's Tiresias Infofont. Please download & enhance it!

About The Author

Mike Gifford is the founder of OpenConcept Consulting Inc, which he started in 1999. Since then, he has been particularly active in developing and extending open source content management systems to allow people to get closer to their content. Before starting OpenConcept, Mike had worked for a number of national NGOs including Oxfam Canada and Friends of the Earth.