'Mermaid' Optical Illusion Leaves People Completely Baffled

A viral optical illusion has left people confused on social media.

The post was shared with a caption stating that those who are right-brained will see a fish, those who are left-brained will see a mermaid.

However, most people saw completely different animals that included neither a mermaid or a fish.

Personally, we saw a donkey so we're not sure what that means.

Others were quick to share their guesses, including celebrities.

Johnathan Ross, weighed in when replying to author David Baddiel, who also saw a donkey.

Ross said: "It’s a plump seal lying in its back. YOU’RE a donkey."

Actress Amanda Abbington also saw a 'seal', which after a bit of squinting we saw too.

J.K Rowling also saw a 'donkey', with Hart Hanson adding 'If it’s a donkey then it’s wearing eyeliner'.

Many were in agreement that the illustrated figure was more donkey/seal than fish/mermaid, with one user noting: "I saw a donkey until I read some people see a seal now it is both. Top donkey bottom seal depending on where I look!"

Another added: "I see a donkey or a seal. I don’t see a mermaid or fish. What does that make me? Alien?"

While it's unclear whether the picture actually shows which side of your brain is more dominant, it's not the first time an optical illusion has caused intense debate. Who could forget the infamous white and gold/blue and black dress debate?

It's white and cold btw, we know the original dress was blue and black but the exposure on the photo makes it look white and gold.

Still, whether it's the colours of a dress or a donkey/seal, why do we see optical illusions differently?

Reportedly, it has to do with the properties in the visual areas of the brain and how they receive and process information.

So, an optical illusion, despite it's name is more to do with your brain than your eye.

Susana Martinez-Conde, of the Barrow Neurological Institute in Arizona said: "An illusion is a phenomenon in which our subjective perception doesn't match the physical reality of the world," as per ABC.

While most are to do with how we process information, some can occur due to properties of the eye, like 'floaters' which are those odd squiggly lines/spots some people see in their vision.

Either way, this illusion is definitely a donkey.