Dyslexia is a specific developmental condition of neurobiological origin. It affects phonological processing — the mapping of sounds to letters — and, in a subset of those affected, the visual processing of symbols as well. Estimates suggest tens of millions of adults across the world live with some form of reading or spelling difficulty. For a digital product, that means a meaningful share of its users will meet every unclear structure, every restless animation, every overloaded sentence first.

A common image claims dyslexic readers see letters dance across the page. That image comes from simulation exercises built to give non-dyslexic people a felt sense of the difficulty — it does not describe what most people with dyslexia actually experience. The core of dyslexia is phonological, not optical. The brain needs more time and more effort to connect a letter with its sound. Nothing necessarily blurs. It is a slower, more effortful translation process that consumes capacity needed elsewhere.

The closest explanation for someone without dyslexia: it is like reading a text in a language you have studied for exactly one year. Every word is recognizable, but nothing runs automatically. You have to actively decode instead of simply perceiving — and by the time you reach the end of the sentence, the beginning has already lost its clarity again. A second analogy lands even more directly for digital products: it is like filling out a form with too many required fields at once while someone stands next to you, timing you. The information is there. But the pressure and the number of simultaneous demands produce errors that have nothing to do with comprehension.

3.1 Typography as Foundation

The choice of typeface is not an aesthetic preference. It is a question of structural stability. Sans-serif faces like Arial, Helvetica, or Inter give the eye less surface area for disorientation — they are the exposed concrete of typography. Just as important is the distinctness of individual characters: "l", "I", "1", and "O", "0" are classic confusion pairs. Specialized typefaces such as Atkinson Hyperlegible or OpenDyslexic reinforce the base forms of letters, reducing the risk of mixing up similar characters and easing the visual-stress effect for the people who experience it.

Rhythm matters as much as the typeface itself: generous line spacing, at least 1.4 to 1.6 times the font size, and short line lengths of 60 to 75 characters keep the eye from losing its place. Whitespace here is not empty space. It is the necessary distance between the load-bearing elements of a page.

• Serif fonts in body text. Flourishes create visual noise and cause letters to "snag" on one another.
• Fully justified text. Uneven word spacing — the "rivers" that run through justified text — disorients the eye. Left-aligned is the more reliable choice.
• Ultra-light font weights. Contrast drops too low, and letters lose weight and blur.
• Pure black on pure white. Glares and intensifies visual stress. Dark grey on off-white or cream reads calmer — calm authority over contrast shock.
• Autoplay video and restless animation. They are cognitive muggings: they steal attention that reading needs.
• Dense walls of text. Long paragraphs with no structure trigger fatigue and the cognitive veto against taking information in.