- Letter scramble
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The inner letters of a word are shuffled while the first and last
letters stay put. This is the original 2016 effect. You can also
include the first and last letters for a harder, full anagram.
- Letter flips (b / d / p / q)
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The classic confusable pairs are mirrored or flipped, the reversal
errors many beginning and dyslexic readers report.
- Jumping letters
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Letters switch places with the word directly above or below them,
so the eye keeps losing its place between rows — an experience
dyslexic readers have reported. Letters with nothing above or
below — at the start or end of the text, or beside a paragraph
gap — stay put, because there is nothing to switch with.
- Letter fragments
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Part of every letter is removed, so each word must be decoded
slowly. Lower removal sizes echo the dyslexic effort of decoding;
higher sizes evoke a low-vision experience of black text on white,
where the white overpowers the characters. It was inspired by
Daniel Britton’s Dyslexia typeface, which simulated
visual perceptual anomalies.
- Perception alphabet
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A per-letter distortion — mirroring, rotation, baseline drift, and
fading — that approximates how some people with learning or
developmental disabilities describe seeing characters:
unstable shapes that shift and reverse rather than sitting still.
- Visual wobble
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Letters drift and tremble, so the line never holds still — a
reading disorder some people experience. The Speed and Intensity
sliders show the range of movement different readers describe, and
how distracting it is to read against.
- Blur / focus drift
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Focus slips in and out — the way tired eyes lose a sharp edge, the
way some people with low vision experience text on white
backgrounds, and the way text can look before someone starts
wearing glasses.
- Crowding
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Spacing tightens until letters and words press together and the
white “rivers” between words vanish — a reading
experience described by people with dyslexia, Irlen Syndrome, and
other reading disorders, and sometimes by those prior to wearing
glasses.
- Black-hole lens (vision field loss)
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A movable field of vision loss that bends, or
“refracts,” the text at its edge. Tunnel
is the Retinitis pigmentosa experience: peripheral vision
is lost first, so a clear window survives at the centre while
darkness closes in from the edges — reading shrinks to scanning a
narrow tunnel. Central scotoma inverts it into a
dark hole that sits over wherever you look, hiding the very thing
you are trying to read; that pattern is closer to macular
degeneration than to RP, and is labelled as such. The refraction
can magnify the text outward or, with
Pull inward, pinch it into the field edge like a
true black hole. Because the loss moves with the eye, the lens can
follow your pointer, drift on its own, or be placed with the X / Y
sliders. There is also a for-fun option to render
an actual black hole — a glowing event horizon and accretion ring —
where the dark spot sits.