What Optical Illusions tells us about Dyslexia

Dyslexics can experience images that appear to flicker, move, rotate, float or change. But actually, ALL people experience these things.

  • When visual effects trick us with images, we label the IMAGE: the IMAGE is an optical illusion.

  • When visual effects trick us with text, we label the PERSON: the PERSON is dyslexic.

But actually text can also be an optical illusion. What is and isn’t an optical illusion is subjective. Some images appear inherently unstable to most brains and some only to a few. Not all optical illusions 'trick' all people - it depends on fine tuning of perception processors in the brain - but all people can be made to experience images which appear to flicker, move, rotate or float.

Let’s look first at a stable image, such as this tree. In the time allotted for perception, which is about 1/75th of a second, the brain does not process the shape of every branch. Instead, it’s more efficient to process just a few samples. These measurements vote on what memories (clusters of previously stored measurements) are a good match. From even 1 or 2% of the possible measurements, the brain can connect to previous memories of trees. As the eye continues to look at the image, more measurements are taken and more votes and connections are made. But ALL of these say the same thing. They just reconfirm that the image is a tree. You might notice new details to refine the original conclusion, but not anything that contradicts it. Most natural images are very repetitive. and the brain is optimized for that type of image.

A leafless tree with a red circle highlighting a section of one branch.

But this optimization doesn’t work well for the images below. They appear unstable to most people because the brain’s ‘voting’ system of perception is coming up with slightly varying conclusions from moment to moment, depending on which subset of measurements is processed in each frame of voting. 

This may appear to flicker:

Colorful optical illusion with concentric starburst patterns in blue, yellow, and orange creating a dizzying spiral effect.

In this example, peripheral votes are not aligned with the votes in your narrow focal point. The image has two circles which never cross but appear to move or cross, especially in your peripheral vision or as your focal point moves around the image.

Optical Illusion showing Two intertwined black and white checkered circles on a gray background.

The center section may appear to be a separate block from the outer image, especially as you scroll:

Optical Illusion showing two sections of wire mesh that appear to move relative to each other, even though they are static

The sections may appear to rotate, especially as your eye moves around the center.

Optical illusion of a Blurred digital swirl with red and purple colors, which appears to spin, even though it is static

These illusions trick 80-90% of people, but the percentage of people varies by illusion. B&W text is an optical illusion for about 5% of the population. 

Imagine reading a whole book that was moving or flickering? It's exhausting. The goal of RexLex is to alter the text in ways the brain finds easier to process, breaking the optical illusion and stabilizing the text.