THIS mind-boggling optical illusion has left puzzle fanatics scratching their heads searching for the answer.
Test your IQ and observation skills by trying to find the face hidden in this picture of a dog.
For those puzzle-heads among you, there's an added catch: you have to try and find the face within nine seconds.
So, grab a timer, set it to nine seconds, and prove your puzzle skills.
Although it may seem easy, with nothing other than a dog on the page, 99% of people have failed to find the face.
Optical illusions are purposefully designed to trick our vision, and can be used as simple determiners of intelligence.
By attempting them we can learn how to make our eyes and brain work together to see better.
They are widely regarded to help improve our attention spans, concentration, and overall cognitive abilities.
Optical illusions where you have to find an image within an image aids your brain's ability to interpret ambiguity.
It helps to keep your brain sharp and young.
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This illusion is made particularly tricky through the lack of colour, as your eyes find it hard to focus on the lack of variety and difference.
Have you spotted the face yet?
If you'd like some help, try breaking the image down into several sections. Then search each section slowly, one at a time.
If you found this puzzle too easy, try our other brain teasers.
Test your vision with this puzzling photo of a cat hidden in a garden.
Not only does it blend perfectly into the background, but you only have 13 seconds to find it!
Or test your IQ by trying to find the mistake in this depiction of a potential problem on the road.
The image shows a red car on a seemingly-idyllic countryside drive, but there's something wrong - and you have to find out what that is.
Why not compare your eyes to that of a dinosaur expert and see if if you can spot the extinct beast lurking in a flock of birds.
Only a very select few have actually succeeded.
But, have you found the face hidden inside the image of the dog yet?
If you couldn't find the face within nine seconds, don't worry, we have the answer for you.
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Try turning the image of the dog 90 degrees to the right.
That's right, the face was perfectly masked in the dog's ear.