One of the most overlooked yet critical aspects of web accessibility standards. The WCAG 2 standard offers almost no guidance on font selection, yet the impact is profound. Many people with various disabilities struggle to read and understand text. Some have visual perception issues and difficulty recognizing letters. Others have spatial processing challenges and struggle to comprehend full sentences because of uneven spacing between words (a problem caused by text justified to both margins). Font size also affects people with visual impairments.
In an era of smartphones and computer screens, these challenges are intensifying for children. Kids with reading difficulties find it extremely hard to work with unreadable screen text. Inability to read causes shame and avoidance of reading aloud. Beyond that, children trying to copy text from the screen struggle to match the letter shape on screen to the shape on their keyboard. Worse still, as reading difficulty increases, their information processing capacity drops significantly. This creates a gap between their verbal and non-verbal thinking.
On top of all these issues, certain fonts make it harder for people with memory, attention, and concentration problems to retain content.
Accessible vs. Inaccessible Fonts
On screens, there's no physical object—only light projected at different speeds and frequencies. Your brain is constantly analyzing what you see without pause, unlike with printed material. This is why you need to look away from screens every 90 minutes. The problem today is that when we look away from our computer screen, we turn to our smartphone.
Take a look at the following image:
On the right is David; on the left is Arial. Notice how David has many diagonal strokes and "serifs"? See the next image to understand what I mean.
When letters are composed of too many diagonals and "serifs" (marked in the red circle), they cross many incomplete pixels, forcing our eyes to work much harder to read. This is how our eyes perceive the letter:
You can see there's really no sharpness in the letter itself. This exhausts the eye and it won't be able to continue like this for long.
Recommendation: Use Sans Serif fonts.