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Editor's Notes

1. I want to start by asking ¡°why talk about typography and dyslexia?¡±
2. The simple answer is that how typography, or how text is presented on a page or screen, has a big impact on how easy it is to read.The two paragraphs above contain the same text, are in the same font, and take up the same area on the screen, but how other aspects of typography are manipulated changes how readable the text is.
3. Beyond that, there is also a really significant amount of anecdotal evidence that suggest typography has a lot of impact on how accessible text is to individuals with dyslexia, and many people with dyslexia find ways to manipulate type to make it more accessible.The British Dyslexia Association has also created a style guide (http://www.bdadyslexia.org.uk/about-dyslexia/further-information/dyslexia-style-guide.html) based on common things that people with dyslexia report about typography, which is a good starting point for investigating what aspects of typography could help.Finally there is a really significant amount of research particularly within the last three years that demonstrates that adjusting specific components of typography can improve readability for people with dyslexia.
4. But before I go into that research, I would like to talk about some myths about how individuals with dyslexia perceive and experience text.
5. This is an image that I pulled down from a site that is one of the top five google hits for the search phrase ¡°Dyslexia and web design.¡±The article that this website uses as evidence for this blur effect looks academic but is self published, and while it talks about a blurring effect, it doesn¡¯t include an image like this and it doesn¡¯t cite or provide any evidence for this supposed effect.I don¡¯t want to totally dismiss this because I can¡¯t personally speak for the experience of every person with dyslexia, and difficulty focusing on text is probably an exacerbating effect for some individuals with dyslexia specifically dyslexics who also have vision problems. But for me, finding something like this on a website about good design for dyslexia is frustrating because, as someone with dyslexia myself, this isn¡¯t what I see when I look at text, and there is no scientific evidence that this supposed effect is caused by dyslexia.
6. Dyslexia isn¡¯t fundamentally about visual distortions, its primarily about how people process letters cognitively.As someone with dyslexia myself, when I look at this image, I see the same letter that everyone else does. That is, I see an oval connected to an ascending line on its right. What's difficult for me is recalling the sound that this letter makes and the name associated with it, and also remembering the order of letters in words, both when I read and when I write.But this doesn¡¯t mean that visual distortions don¡¯t play a role in the readability of text for individuals with dyslexia.
7. Lateral masking (sometimes called crowding) is a visual distortion that everyone, including people with and without dyslexia experience, but there are documented differences in how people with dyslexia experience it, which may affect the readability of text for them.In general people experience more lateral masking in their peripheral vision than in their central (foveal) vision, but individuals with dyslexia experience it less strongly in peripheral vision than others, and may experience it more strongly in central vision (Lorusso, Facoetti, Pesenti, Cattaneo, Molteni, & Geiger, 2004; Geiger, Lettvin, & Zegarra-Moran, 1992; Perry, Dember, Warm, & Sacks, 1989; Geiger, & Lettvin, 1987). One possible explanation for lateral masking is that it¡¯s a kind of blinder that makes it easier for people to focus on their central vision, and that because people with dyslexia experience it less in the periphery it makes it more difficult for them to distinguish letters in their central vision (though individuals with dyslexia may also experience more lateral masking in their central vision than the average reader).Differences in how people with dyslexia experience lateral masking has been connected with strengths that people with dyslexia have in task that require processing images as a whole (Schneps, Rose, and Fisher 2007).ReferencesGeiger, G., & Lettvin, J. Y. (1987). Peripheral vision in persons with dyslexia. New England Journal of Medicine,?316(20), 1238-1243.Geiger, G., Lettvin, J. Y., & Zegarra-Moran, O. (1992). Task-determined strategies of visual process.?Cognitive Brain Research,?1(1), 39-52.Lorusso, M. L., Facoetti, A., Pesenti, S., Cattaneo, C., Molteni, M., & Geiger, G. (2004). Wider recognition in peripheral vision common to different subtypes of dyslexia.?Vision Research,?44(20), 2413-2424.Schneps, M. H., Rose, L. T., & Fischer, K. W. (2007). Visual learning and the brain: Implications for dyslexia.?Mind, Brain, and Education,?1(3), 128-139.
8. The issue of lateral masking, which all users experience in one way or another, demonstrates that typography and readability for individuals with dyslexia is a universal design issue: improving readability for dyslexic readers has a lot of potential to improve it for the average reader as well.
9. When done well, letter spacing can increase the legibility of text (how easy it is to discern individual letters).Asa result letter spacing is one of the typographic elements that has the most promise for improving readability for individuals with dyslexia for two reasons: 1) individuals with dyslexia are more likely to rely on identifying each letter when decoding a word, and 2) by increasing the spacing between letters you are directly affecting lateral masking.
10. In three separate studies, increasing letter spacing has been demonstrated to improve readability for people with dyslexia, especially the dyslexic readers with the least developed literacy skills.ReferencesPerea, M., Panadero, V., Moret-Tatay, C., & G¨®mez, P. (2012). The effects of inter-letter spacing in visual-word recognition: Evidence with young normal readers and developmental dyslexics. Learning and Instruction, 22(6), 420-430.Zorzi, M., Barbiero, C., Facoetti, A., Lonciari, I., Carrozzi, M., Montico, M., Bravar, L., George, F., Pech-Georgel, C., & Ziegler, J. C. (2012). Extra-large letter spacing improves reading in dyslexia. Proceedings of the National Academy of Sciences, 109(28), 11455-11459.Schneps, M. H., Thomson, J. M., Sonnert, G., Pomplun, M., Chen, C., & Heffner-Wong, A. (2013). Shorter lines facilitate reading in those who struggle. PloS one, 8(8).
11. Line length has been demonstrated to have an affect on readability, and there are many rules of thumb about appropriate line length relative to font size and line height, but a recent study has demonstrated that these rules of thumb should be modified for people with dyslexia.
12. One of the most thorough and sophisticated studies on dyslexia and typography investigated how mobile technology affected the readability of text for individuals with dyslexia (Schneps, et. al. 2013) which found that line length has a significant effect on readability.This study was lead by Matthew Schneps, a dyslexic astronomer who noticed that reading on his smart phone was easier for him than other mediums and setup the study to investigate and validate this phenomenon. One of the key findings from this study was that extremely short line length (2¨C3 words per line) greatly improved readability.I¡¯ve included a picture of my own phone (a Galaxy S3) using an app called ¡°pocket¡± to display the text of a blog article with extremely short line length, because this is a phenomenon that I have experienced as well. ReferencesSchneps, M. H., Thomson, J. M., Sonnert, G., Pomplun, M., Chen, C., & Heffner-Wong, A. (2013). Shorter lines facilitate reading in those who struggle. PloS one, 8(8).
13. This study used sophisticated eye tracking techniques (in the above image taken from the study paper, the blue lines represent the path this particular participant¡¯s eyes took as they read this passage). These techniques allowed the researchers to examine the reading patterns of its participants. Through this, they discovered that while short line length increased the number of times participants had to go back to the left margin, it also dramatically decreased the number of errors caused by doing this, improving readability.Again, this is a phenomenon I can personally attest to. As a child, one of the most difficult things about reading was getting to the beginning of the next line when I was done with the first. This often took extreme concentration, and introduced a high number of errors in my reading processes, both of which usually meant that getting to the next line took so much focus and time that by the time I did it right I had forgotten what I had read in the previous line. This made it very difficult to understand text, especially when sentences broke across the line (which they do in nearly every case).Shcneps et. al. also speculate that these extremely short line lengths could benefit normal readers as well.
14. ReferencesSchneps, M. H., Thomson, J. M., Sonnert, G., Pomplun, M., Chen, C., & Heffner-Wong, A. (2013). Shorter lines facilitate reading in those who struggle. PloS one, 8(8).