Focus on one dot, and the rest will nope out and vanish.
What: Some dots are here to stay, and others disappear, or at least that’s how it goes in this illusion, fantastically named an Extinction Illusion, named by its creator Jacques Ninio [1] … In this optical toy when you focus a single dot you’ll see (or not see?) that the other darker dots vanish, while it goes against my intuition, it’s named here as a variant of the Hermann Grid
How To: You can customize more or less this whole thing! The thickness of the lines for me is a key piece to make the illusion stronger, as well as getting the contrasts into place, but you’ll also see that certain color clashes get it working just as well. You’ll also see that the distances between the areas are pretty important.
Explain it: If this is anything like the Hermann Grid the “how” is relatively uncertain, that said the illusion gives a feeling not so dissimilar to the Troxler Fade where some information is lost to the brain as it focuses on a single stimuli.
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 toymaker@toms.toys, be kind!