Optical illusions can trick the brain into seeing things that aren't there and leave you feeling baffled, but their tricky nature also makes for a great brain workout.
While you might struggle to solve some illusions and brain teasers at first, you'll get better with practice, and before long you'll be able to crack them in seconds, as they work wonders for our cognitive function by improving the brain's ability to perceive and interpret visual information.
If you're looking to set yourself a challenge, why not check out this optical illusion below? At first glance, the image looks as though it's moving as the spirals keep spinning - but it's actually completely still.
The image, from the online slot site Rainbow Riches Casino, is designed to trick the brain into thinking that the spirals are spinning, thanks to the contrasting colours and repeated patterns.
Try looking directly at one of the spirals - do all the ones surrounding it start moving?
The movement is caused by your brain filling in the gaps in your peripheral vision, or the areas outside of your direct line of sight, and thanks to the bizarre colours and patterns in the image, your brain has a hard time filling the gaps in while keeping the image completely static.
However, there is a way to stop letting the illusion play tricks on you.
If you focus on looking at just one part of the illusion for 10 seconds, your brain will adjust, and the image will no longer move. Can you make it stay still?
If your appetite for puzzles isn't quite whetted enough, why not try your hand at some of our other favourite brain teasers and optical illusions?
This one challenges you to find the hidden tools within just 40 seconds - and it's claimed only 20% of people can solve it.
Or why not try this one, which asks you to find the snail buried among the sea of creatures within 20 seconds?
And if you want to try a different sort of puzzle, this image shows three runners in a race, but one of them is cheating - can you work out which one?
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