Words don’t dance, swim, or rearrange themselves on the page for most people with dyslexia. That viral simulation you may have seen online, where letters swap positions in real time, was called “quite misleading” by Sally Shaywitz, co-director of the Yale Center for Dyslexia & Creativity. The reality is more nuanced and, for many people with dyslexia, not primarily visual at all.
What Popular Simulators Get Wrong
A well-known online simulator created by developer Victor Widell shows letters within words constantly shuffling positions. It went viral because it feels disorienting to read, and that disorientation does capture something real: the frustration many dyslexic readers experience. Jerome Schultz, a clinical neuropsychologist at Harvard Medical School, noted the simulator can “create empathy” and help non-dyslexic people appreciate how exhausting reading can be for someone who struggles with it.
But the simulation doesn’t reflect the actual experience for most people. Jordan Jones, a college student with dyslexia, put it simply: “I do read slow, but that simulation is not how I see the words when I read. In no way for me personally was that accurate.” Fernette Eide, co-founder of Dyslexic Advantage, estimated that roughly one-third of dyslexic individuals have visual issues, and most of those “are not that severe.” If dyslexia were as visually debilitating as the simulator suggests, she noted, most children and adults wouldn’t show positive progress with appropriate instruction, which they do.
How Dyslexia Actually Affects Reading
For most people with dyslexia, the core difficulty isn’t seeing the letters incorrectly. It’s connecting those letters to the sounds they represent. This is called a phonological deficit: the brain struggles to break words into their component sounds and match those sounds to letter patterns. Think of it like this: you can see the word “catastrophe” perfectly clearly on the page, but your brain takes significantly longer to decode it into a sequence of sounds that form a recognizable word.
Brain imaging studies consistently show that dyslexic readers have reduced activity in the left side of the brain, particularly in regions responsible for converting visual letter patterns into sounds. In typical readers, a region sometimes called the brain’s “letterbox” rapidly recognizes whole words almost on sight. In dyslexic readers, this region is underactive, forcing the brain to work harder and slower to decode each word. The result isn’t a visual distortion. It’s a processing bottleneck.
That said, there is genuine scientific debate here. A competing theory argues that dyslexia stems from dysfunction in the visual pathways that handle rapid processing of moving or changing stimuli. Recent research has found evidence supporting visual processing problems as a root cause in some cases. The truth likely varies from person to person, which is part of why dyslexia looks so different across individuals.
Visual Experiences Some Readers Do Report
While dyslexia isn’t primarily a vision problem for most people, a meaningful minority do experience genuine visual disturbances when reading. These can include blurred text, words that seem to shimmer or vibrate, letters that appear to drift, and difficulty keeping their place on a line. Some readers report that the white spaces between words or lines seem to dominate the page, creating distracting vertical “rivers” of white space that pull attention away from the text itself.
Eye-tracking research reveals part of the mechanism behind these experiences. Dyslexic readers tend to make more unintended eye movements while trying to focus on a fixed point. Their eyes also jump backward more frequently during reading, revisiting words they’ve already passed. This isn’t a conscious choice. It reflects instability in how the eyes coordinate during the fine-grained task of scanning text. The result can feel like the text is moving when it’s actually the eyes that are struggling to stay steady.
A related condition called visual stress (sometimes referred to as Meares-Irlen Syndrome) involves sensitivity to the high contrast of black text on white paper. Studies estimate that 20 to 34 percent of the general population experience some degree of visual stress, and it may be slightly more common among dyslexic readers, though the difference isn’t large enough to be statistically significant in most studies. People with visual stress often benefit from colored overlays or tinted lenses, which reduce the contrast that triggers discomfort.
The Crowding Problem
One visual challenge that does disproportionately affect dyslexic readers is crowding: the way nearby letters interfere with each other when packed tightly together. For most readers, the brain efficiently separates neighboring letters. For many dyslexic readers, tightly spaced letters blur together into a harder-to-decipher mass. It’s not that the letters look physically different. It’s that the brain has more trouble distinguishing them from their neighbors.
Research on this effect is robust. When letter spacing is widened even slightly, readers respond faster and fixate on words for less time. Increasing line spacing produces similar benefits, with readers skipping more filler words (a sign of easier processing) and spending less time on each fixation. This is one of the most practical findings in dyslexia research: simply giving letters more breathing room can make a measurable difference.
What About Letter Reversals?
The idea that dyslexic readers see letters backward, confusing “b” with “d” or reading “was” as “saw,” is probably the most persistent belief about the condition. The reality is more complicated. Some studies do find that children with dyslexia make more reversal errors, but others find little or no difference between dyslexic and non-dyslexic children. What’s clear is that letter reversals are extremely common in all beginning readers, dyslexic or not. Most children confuse mirror-image letters while learning to read and grow out of it.
The early theory, proposed by neurologist Samuel Orton in the 1920s, was that dyslexic brains failed to suppress mirror images of letters. This idea shaped public understanding for decades, but modern research treats it as just one piece of a much larger puzzle. Reversals, when they do persist, are more likely a symptom of difficulty with letter-sound associations than a sign that letters literally appear flipped.
How Reading Speed Differs
Where dyslexia’s impact shows up most clearly is in reading speed and fluency. In one study of children aged 7 to 10, dyslexic readers in second grade averaged about 62 words per minute compared to 103 words per minute for non-dyslexic readers at the same grade level. By third and fourth grade, dyslexic readers had improved significantly (reaching 107 to 113 words per minute), but still trailed their peers. The gap narrows with age and instruction, but reading typically remains slower and more effortful.
This slower pace is what many dyslexic adults describe as their primary experience. Words don’t look wrong. They just take longer to decode. Reading requires more concentration, causes more fatigue, and demands re-reading passages that a non-dyslexic reader would absorb in a single pass.
Do Special Fonts Help?
Several fonts have been designed specifically for dyslexic readers, including Dyslexie and OpenDyslexic, which use heavier bottom weighting and varied letter shapes to make characters more distinct. The idea is appealing, but the research is discouraging. In a study of 170 children with dyslexia, reading text in Dyslexie font was no faster or more accurate than reading in Arial. A second experiment with 147 children, both with and without dyslexia, confirmed the same result across Dyslexie, Arial, and Times New Roman. Multiple other studies comparing OpenDyslexic to standard fonts found no significant differences in speed or accuracy either.
One study did find that Dyslexie font appeared to produce a slight advantage, about 7 percent more words read per minute, but when researchers controlled for spacing (Dyslexie naturally has wider letter and word spacing than Arial), the benefit vanished. The spacing was doing the work, not the letter shapes. This aligns with the crowding research: wider spacing genuinely helps, but you don’t need a special font to get it.
For practical purposes, choosing a clean sans-serif font at a comfortable size with generous spacing will do as much as any specialty typeface. Avoiding justified text alignment, which creates uneven word spacing and those distracting rivers of white space, also helps.