An optical illusion has gone viral as it puts your eyesight to the test.
The swirling black and white image contains a series of numbers, but how many can you spot?
A huge number of people have been trying it out after the illusion was shared on Twitter.
The illusion is a measure of contrast sensitivity, which allows us to perceive the difference between objects and their backgrounds.
According to Vision Center, contrast sensitivity is an important aspect of visual function.
Explaining what it all means, its website reads: "Contrast sensitivity is an important measure of visual function, especially in situations of low light, fog or glare, when the contrast between objects and their background often is reduced. Night driving is an activity that requires good contrast sensitivity for safety."
The answer
The majority of people report seeing 45283, with some only spotting 528.
However, the real answer is 3452839.
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