It would be revolutionary if the reading performance of children and adults with dyslexia could be improved by using a special font. This is exactly what a Dutch graphic designer, Christian Boer, aimed to do when he developed the font “Dyslexie” in 2008.
Dyslexie has been used in several primary schools in the Netherlands, and Dutch publishers have printed books in this font. Since 2011, the font has also become more prominent in English, and English-speaking countries such as Australia have started to print books in Dyslexie. The font has received a lot of media attention worldwide (e.g., TheGuardian.com, Slate.com, TheAtlantic.com, USA Today, and io9.com).
A study by Marinus et al. (2016) aimed to examine if Dyslexie is indeed more effective than a commonly used sans serif font (Arial) and, if so, whether this can be explained by its relatively large spacing settings.
Participants were 39 low-progress readers who were learning to read in English. They were asked to read four different texts in four different font conditions that were all matched on letter display size (i.e., x-height), but differed in the degree to which they were matched for spacing settings. Results showed that low-progress readers performed better (i.e., read 7% more words per minute) in Dyslexie font than in standardly spaced Arial font. However, when within-word spacing and between-word spacing of Arial font was matched to that of Dyslexie font, the difference in reading speed was no longer significant.
The authors conclude that the efficacy of Dyslexie font is not because of its specially designed letter shapes, but because of its particular spacing settings.
Video: Dyslexia intervention
Marinus, E., Mostard, M., Segers, E., Schubert, T. M., Madelaine, A., & Wheldall, K. (2016). A special font for people with dyslexia: Does it work and, if so, why? Dyslexia, 22(3), 233–244.