First there was the dress.
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(you know the one, the stripped dress that was either blue and black, or white and gold, depending on what you saw)
Then there was the great Laurel or Yanny voice clip debate.
And now its dog or clown, as another optical illusion divides the internet.
This time a picture has social media users debating if they see a cute dog - or a scary clown.
Here's the photo, so you can decide for yourself:
As always the internet can't just accept people might be able to see one, the other, or indeed both, so off the debate runs.
Reddit users (where some sources are reporting the image was first posted) have a long thread discussing it, and Twitter is also alive with the debate.
And then there's these responses: