Some optical illusions are really mind-blowing and this one is going to freak you out.

There are 12 black dots on this image, but you can’t see all of them at once. Try to, and you’ll send yourself mad.

It’s called an extinction illusion, and works on the principle that light receptors in your eyes sometimes get confused with the ones next to them. This can make you not see things that are in front of you and vice versa.

Imgur: The most awesome images on the Internet

This particular one was created by J Ninio as a variation on the Hermann grid.

Apparently, it works even if you invert the colours. It actually made us feel a little bit ill, and we’re not the only ones.

@wkerslake @debreuil mouth literally hanging open. wtf, brain???

— Keith Peters (@bit101) September 12, 2016

@wkerslake @joshuakrohn welp, you just broke my brain

— Luke Dooley (@yeloodekul) September 12, 2016

Others were ready to show off.

@wkerslake @SpeakOnion ??? I see them all just fine

— Mo (@megans_law) September 12, 2016

@wkerslake of course you can see the 12 dots

— Claudia Papo (@claudiapapo) September 12, 2016