Dyslexia is a learning disability that is usually defined as an unexpected difficulty in reading, spelling, or writing but it can also occur across a range of other intellectual abilities.
It’s a result of disruptions to brain processes dealing with written language that may be caused by genetics, although its specific causes still remain unclear.
Symptoms of Dyslexia
Though the symptoms of dyslexia may vary for each individual, they typically include:
- Reading and writing slowly, especially when reading out loud
- Confusing similarly spelled words
- Adding, missing, or mixing up letters in a word (e.g., p and q)
- Spelling erratically
- Needing to re-read the same section several times to understand its meaning
- Finding it hard to listen, concentrate, and/or maintain focus
- Feeling sensations of mental overload, etc.
People who have dyslexia can also experience issues with self-esteem, particularly in cases when its symptoms haven’t been identified earlier in the life of a child.
Dyslexia is the most common neuro-cognitive disorder. According to the Yale Center for Dyslexia And Creativity, it affects approximately 20 percent of the total population. Dyslexia also represents 80-90% of all people with learning disabilities.
For people with dyslexia, choosing the right website font can drastically improve user experience. In order to make web content fully accessible to people with dyslexia, content creators should take dyslexia-friendly fonts into their web design considerations.
Do Dyslexia-Friendly Fonts Work?
When web designers use fonts where words are closely packed or squished together, it may make it hard for people with dyslexia to identify the words. Choosing a font that is not easily readable for people with dyslexia means that at least 20% of your potential customers may have a difficult time using your website.
Yes, dyslexia-friendly fonts do work, but it’s important to keep the following guidelines in mind when choosing the right font for your website:
- It’s generally preferred to use sans serif fonts that are designed without serifs (i.e., extending features at the end of strokes) thus helping the letters appear less crowded (though we’ll also note some serif font exceptions below)
- Font size should generally be 12-14 point, though some people with dyslexia may prefer a larger font size
- Don’t underline and italicise words; instead, apply bolding if necessary for emphasis
- Don’t use all capital or uppercase letters; lower-case letters are preferable
- Character spacing should be larger, ideally approximately 35% of the average letter width
- Larger line spacing can also improve readability, such as 1.5 instead of 1
- Headings should use a font size at least 20% larger than normal text
What is the OpenDyslexic Friendly Font?
There are certain fonts that are specifically designed for users with dyslexia, such as OpenDyslexic.
OpenDyslexic is a free font, which is designed to reduce some of the most common reading errors that are typically caused by dyslexia. It uses heavier lines and unique character shapes that aim to increase readability for readers with dyslexia and make it easier for them to distinguish between different letters.
However, rigorous research has demonstrated that using this font did not help students with dyslexia show improvement in reading rate or accuracy, and it was not reported as their preferred font.
Other mainstream and widely available fonts may prove to be more effective, although, of course, it’s worth keeping in mind that each user’s preferences may vary.
What Are the Most Dyslexia-Friendly Fonts?
Web Content Accessibility Guidelines (WCAG) do not propose any specific guidelines when it comes to font types or sizes for people with dyslexia.
However, Spanish researchers Luz Rello and Ricardo Baeza-Yates have conducted a study partially funded by the Spanish Ministry of Education and Science that helped them determine the most dyslexia-friendly fonts.
Based on their research, these are the best as well as most widely available fonts that can be used to improve content readability for people with dyslexia:
Arial
Arial is one of the most popular and widely used fonts on the internet. First off, it’s sans serif, which means that letters are not squished together and are more rounded, ensuring clear definition. It’s easy to read, and just as importantly, it’s free and doesn’t require a licence.
The drawback of Arial is that it isn’t monospaced, meaning it isn’t a font designed to have each character the same width. It also shouldn't be italicised because it has a decreased readability when italicised.
Courier
The advantage of Courier is that it’s monospaced, which makes it easier to read for people with dyslexia. It’s also the most commonly used monospaced font. However, it’s not a sans-serif font.
Despite that, Rello and Baeza-Yates found in their study that using Courier led to shorter fixation durations, which refers to the amount of time the eyes rest on a single place of the text. Because of this, Courier may help people with dyslexia read faster.
Helvetica
The other font that led to shorter fixation durations in Rello and Baeza-Yates’ study was Helvetica. This font is particularly popular among major brands and commonly used for public signage, making it one of the most widely used fonts.
Like Arial, Helvetica is not monospaced, but it is a sans-serif font that is clear and easy to read. It was chosen as the second most preferred font by the participants of the above-mentioned study.
Verdana
Just ahead of Helvetica is Verdana, the most preferred font choice of the study’s participants. Verdana was designed specifically for legibility in printed form and on various screen sizes, including computers, phones, and tablets.
Although Verdana is not monospaced, it is sans serif. It’s designed with wide spacing between letters, which is the key to making it easily readable at any size. It’s important to note that the study’s participants preferred Verdana over the OpenDyslexic font.
Other Most Dyslexia-Friendly Fonts
Although not considered in Rello and Baeza-Yates’ study, other dyslexia-friendly fonts may be used by web designers as possible alternatives to the fonts mentioned above.
Comic Sans
Although Comic Sans is often derided by graphic designers, it’s actually one of the most dyslexia-friendly fonts widely available. Designed to mimic the typeface often used in comic books, its playful and irregular design of the letters makes the letters easier to distinguish. Plus, as the name itself suggests, it’s a sans-serif font.
Tahoma
Tahoma is another widely available font that is a bit similar in appearance to Verdana. Microsoft created it with the intention of being easy to read, particularly on smaller-sized screens, e.g., in menus and dialogue boxes. It’s a sans-serif font featuring bold lines and space for each letter, which can be useful for people with dyslexia.
Open Sans
An open-source, sans-serif font designed by Google, Open Sans is also designed for legibility on various interfaces, including print, web, and mobile. It’s similar in appearance to Trebuchet and Calibri, which are also considered dyslexia-friendly fonts. Its style is straightforward, with rounded letter shapes and clear spacing, which is always helpful for people with dyslexia.
Making your content fully accessible to people with dyslexia doesn’t stop at picking the right font.
Here are some other things to keep in mind as you’re designing your web content:
- Left align text without justification
- Make sure there is extra space around each heading and between paragraphs
- Keep paragraphs short and break up the text with an appropriate number of headings
- Hyperlinks should visually stand out from headings and standard text
- Do not use busy or distracting background patterns and pictures; it’s preferred to use a single background colour (e.g., white or off-white)
- Ensure there is a sufficient colour contrast between the text and the background (e.g., black text against a white background)
- Use language that is clear, simple, and succinct; avoid jargon and technical language
- Avoid long and overly complex sentences that may be difficult to comprehend by people with cognitive disabilities; in general, try to keep sentences at 60-70 characters
- Use bullet points and numbering if/when appropriate
- Make sure your content is easily readable on any screen size and in either screen orientation
Read more about WCAG guidelines to find additional tips to help you make your web content more accessible to people with cognitive disabilities, including dyslexia.
