Spot hidden deer in garden picture to prove you have the 'world's sharpest eyes'

Optical illusions and visual puzzlesaren't just a brain workout, they're also a cracking bit of fun.

This one will either leave you feeling chuffed to bits or ready to pull your hair out in frustration. Your ability to spot the hidden deer in this image might well hinge on your eyesight and how eagle-eyed you are.

Optical illusions, brainteasersand other puzzle types are touted as having a raft of benefits for your noggin: they can be a great way to chill out after a tough day at work, boost your memory, and enhance various forms of reasoning - like spatial and visual.

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One study even suggests that tackling a daily crossword can help fend off dementia, particularly in those experiencing mild cognitive impairment symptoms.

All in all, they're worth giving a go - especially because mastering them comes with the ultimate prize: bragging rights.

This seemingly ordinary garden snap hides a deer somewhere within it, and if you can spot it in under six seconds, you might just have top-notch eyesight - and the perfect excuse to send it to all your mates, knowing full well you're likely the most sharp-sighted amongst them. Have a gander below to test your eye for detail.

Struggling to spot it? If it took you more than six seconds, don't worry, our attention spans aren't what they used to be due to our tech-obsessed lifestyles. If you managed to spot the deer in under 30 seconds or even a minute, that's still quite impressive.

On the other hand, if you couldn't find the deer at all, scroll down to discover where it was hiding all this time.

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Now that you know where the deer is, let's delve into the different types of optical illusions you might come across during your puzzle-solving escapades. There are three main types: literal, cognitive and physiological.

The first type, literal, merges two images into one - you might see a bird, whilst your mate sees an elephant. These are the most common type you're likely to encounter.

Cognitive optical illusions are tricksters, targeting your brain and what your eyes perceive simultaneously, and they are often the most complex: we will make a safe assumption about what we see, but the image will contradict it.

Physiological illusions exploit how we process light and colour, static 2D images start to move and create the illusion of depth by overstimulating the brain.