This '3D' optical illusion is the most divisive I've ever seen

A supposedly 3D optical illusion has been posted online and is possibly the most divisive I've ever seen on the optical illusion. Comments are either steadfastly denying any effect whatsoever, with others saying it's one of the best illusions they've seen.

The illusion consists of a patterned set of blue and red circles, set out like a target against a black background. It's meant to appear in 3D (when of course it is completely flat). It's a version of an illusion I've seen before that's very similar but completely plain – and that one always causes division too. Some people blame astigmatism for their failure to see the illusion's effect while others have no explanation. What do you see when you look at it? One of the best optical illusions ever or a total let down? Let me know in the comments.

Look like 3D from r/opticalillusions

See it?

The illusion is called Chromostereopsis, which is the perception of depth that's created by red and blue light hitting your retina at the same time. Your brain processes the two colours at two different wavelengths, creating the illusion of depth – therefore making it a 3D image.

In the Reddit thread, people are discussing the difference perceived by people that wear glasses and people who don't.

"Being near-sighted wearing corrective lenses may be responsible for exaggerating the effect," says one person. "The wavelengths of color get to the eye at different spots through the lens ie: chromatic aberration."

And if you can't see it, try this tip: "I'm on my phone and holding it at arms length and relaxing my eyes. It looks like a hologram with the blue recessed behind the screen."

If you're into colour-based illusions, see this dotty illusion that has people debating whether it's blue or purple.