Watch as this grid repairs itself in the corners of your vision.

What: The Healing Grid illusion is an optical illusion by Scientist Ryota Kanai, and was a finalist in the 2005 illusion of the year competition, with this peripheral trickery.

How To: To get this illusion happening you’ll need to stare into the center, being careful not to look too far to your peripheral vision, eventually there will be a subtle healing of the grid. The effect isn’t staggeringly strong and can take a little while. I find once I’ve got it to heal out once I can replicate it fairly quickly after that.

There are a few options here that may make the effect feel stronger for you, decreasing the variance will mean that there is less “break” which naturally will make it a little easier for your brain to “heal” it so to speak. The colors can also be effective in helping the effect, although for me the higher contrast the stronger the effect.

You can also make the healing grid illusion more powerful by changing the sizes of the squares, or plus symbols (depending on your point of view). The smaller, the stronger the effect.

Explain it: This optical illusion is falling into a similar category to a few on the site, whereby when you’re focusing on a small part of a larger image your brain and optical nerves begin to tire, and start to make a few assumptions about the pereferals. From the paper:

We argue that the uniformity illusion is the result of a reconstruction of sparse visual information (from the periphery) based on more readily available detailed visual information (from the fovea), which gives rise to a rich, but illusory, experience of peripheral vision.

Cites and Extras:

I've researched these optical illusions in my spare time but am clearly not any kind of expert and my explainations are pretty smooth brained, if you find something mis-cited, earlier examples, or general mistakes please new let me know via, be kind!