In recent years, two new typefaces for dyslexics have been created, both by dyslexics trying to ameliorate issues specific to dyslexic readers: Sylexiad by information/book designer and professor Dr. Robert Hillier of Norwich University in the United Kingdom, and Dyslexie by graphic designer Christian Boer of StudioStudio in the Netherlands.
An endeavor such as this sparks many questions. What did the designers interpret the problems to be? What process did they use to arrive at their solutions? How did their solutions differ? How successful are they as typefaces? How does all this relate to what we know about legibility and dyslexia? Most importantly, did they achieve their goals?
What problems were they trying to solve? Boer says Dyslexie is intended to help dyslexics read with less effort, be less affected by the symptoms associated with dyslexia and make reading more accurate. Sylexiad is positioned by Hillier as an ongoing design investigation to make a typeface that would be preferred by adult dyslexics over alternatives.
The success of these typefaces likely depends on just how you define the goals. If satisfying people with dyslexia is the goal—as Hillier says for Sylexiad—then they may have been quite successful, at least with a lot of their target audience. One Dyslexie customer wrote to Boer, “I showed it to a colleague of mine who happens to have dyslexia, and he literally broke down and started crying because he was able to read your info page aloud.” Hillier’s entire methodology for Sylexiad was focused around studying dyslexic readers' typeface preferences.
But if we look at scientific evidence as to whether using these fonts
has (or should have) any measurable effect on dyslexics reading, things
are not quite so clear.WHAT WE KNOW ABOUT DYSLEXIA AND LEGIBILITY
The manual for Boer’s Dyslexie claims that “symptoms of dyslexia are mostly: turning the letters; mirroring the letters; changing the letters.” Unfortunately, although it is a popular belief that these are symptoms of dyslexia, the current scientific understanding of dyslexia says otherwise.
Hillier’s definition (in the thesis for which he developed Sylexiad) matches the current, most common scientific understanding, that dyslexia is “a phonological deficit that influences an individual's ability to decode and encode language.” The phonological
part is important. For the most part, scientists believe the difference between people with dyslexia and non-dyslexic readers lies in their confusing similar sounds, not shapes of letters. It seems there is evidence to support this distinction. This theory does not suggest anything about visual processing and mirroring/rotating letters. Although dyslexics may do this, most research suggests they don't do it much more than anybody else at the same reading level.
Figure 1: Christian Boer’s Dyslexie and Dr. Robert Hillier’s Sylexiad displayed at the same nominal point size. (Not all faces of Sylexiad are shown.) Note the erratic/tight spacing across different styles of Sylexiad Serif for combinations such as “bold” “foin” and “bu” and the excess space on the right side of the lowercase letter “l” in Dyslexie.
Mind you, right after the seemingly false statement about symptoms of dyslexia, the Dyslexie manual says, “By emphasizing the shape of each character there will be less confusion between the characters.” Even though mirroring and rotating may not be problems for dyslexics (or anybody else), it is certainly true that letters that are too similar can be easily confused by readers, whether dyslexic or not. The dominant theory of decoding alphabetic text (as opposed to Chinese, for example) today is parallel letter recognition. Although several words worth of letters are seen at once, the letters within each word are recognized and decoded in parallel by the brain (Larson, 2003). Making these letters more easily distinguished from each other is helpful, and experiments have even identified which parts of letters are important (Gosselin, 2011).
One concern is that dyslexia may not be a single thing, but in fact a label for several different problems with reading, some of which are more common than others. Is it possible that there are those for whom letter rotation and mirroring is a key part of their problems, even if they are a minority of dyslexics? Perhaps. But this would not be the first time that science overruled our perceptions of reality (see Copernicus and the sun not revolving around the earth). Apart from the mirroring/rotation issue, I could find no evidence that dyslexics need different kinds of font legibility enhancement than other readers.
Dyslexia aside, what we know about legibility for all readers, dyslexic and otherwise, suggests that when letterforms are designed with closed shapes such as those in Helvetica and Arial, the glyphs are harder to tell apart from each other than in more humanist typefaces such as Lucida Sans/Grande, Myriad, Frutiger and Gill Sans. I believe Dyslexie is enlightened in that it opened up those counters, but misguided in using Helvetica-style shapes as a starting point in the first place instead of a humanist model (or even a geometric one such as Futura).
Many of the other modifications in Dyslexie are specifically about protecting against somebody’s brain accidentally rotating or mirroring the letters. This includes the increased boldness on the bottom of letters across the entire typeface. It seems clear that unless the research on dyslexia is all wrong, this won't help most (if any) dyslexics. However, a few changes were also made simply to make letters more distinct, such as adding the tail on the lowercase “l.” The lessons of cognitive psychology suggest these kinds of changes could be helpful to all readers, with or without dyslexia.
Figure 2: Samples in Sylexiad Sans, Sylexiad Serif, Dyslexie, Helvetica, and Lucida Sans/Grande, and Gill Sans, adjusted to the same apparent size. Compare the closed counters of Helvetica and the open shapes in Lucida and Gill. Note also the relatively even proportions of the capital letters in Dyslexie and Helvetica compared to the more varied capital letter widths in Lucida and Gill.
Sylexiad seems to have been created from scratch in form, and is overall less daring but perhaps a little more successful. Hillier concentrated a little more on differentiating individual letters. The “n” and “u” each get a right-side serif, even in the sans version of the typeface. Yet he went with the simpler forms of the letters “a” and “g” instead of the more complex (and hence more easily distinguished) forms. The capital letter “I” and numeral one get horizontal bars to help distinguish them from each other, but the lowercase “l” does not.
PROCESS & SOLUTIONS
Sylexiad was designed with an ongoing feedback loop from dyslexic readers (what Hillier calls “developmental typeface testing”). This is a great way of developing a typeface, even if not the innovation that Hillier makes it out to be. Prior to Sylexiad, Hillier went through three iterations of previous experimental typefaces called Dine to learn about some specific variables and how dyslexics responded to them. At the end, serif and sans serif versions of Sylexiad were compared against Arial, Sassoon Primary and Times New Roman. The most striking result was not in functionality, but in personal preferences. According to Hillier:
“The majority of non-dyslexic readers preferred: serif style fonts, lowercase forms, large x-heights, medium weights, variable strokes, normal inter-word spacing and familiarity of form. They also preferred Times New Roman as a family. The majority of dyslexic readers, however, preferred: handwritten-style fonts, uppercase (Sylexiad) forms rather than lowercase forms, long ascenders and descenders, light weights, uniform strokes, perpendicular design, generous inter-word spacing and, as with the control, familiarity of form. Unlike the control they preferred Serif Sylexiad as a family.”