Optical illusion photo of a man goes viral as people can't work out which body part it shows - so can YOU figure it out?

More from Science & Technology

• Earthquake strikes Kansas above ancient volcanoes buried deep underground

• NASA names astronaut who suffered life-threatening emergency that triggered historic space evacuation

• Secret mind-control techniques using TVs revealed in disturbing patent

• 'Largest breach in US history' exposes social security numbers and health records of 26 MILLION Americans… see if you're at risk

• Blood moon over US ignites fears of biblical end-times warning

• Emperor penguins are on the pathway to EXTINCTION: Satellite images reveal how shrinking sea ice is forcing birds into crowded groups - with potentially 'catastrophic' consequences

• Earth's 'Doomsday Vault' has been updated: Scientists add 7,800 samples into the secretive bunker in the Arctic

• Ey up AI! Scientists are teaching artificial intelligence how to understand UK accents and dialects - so, how many of these regional terms do YOU know?

• See the Milky Way like NEVER before: Largest image of its kind reveals the hidden chemistry at the heart of our galaxy

• What will happen to Punch the monkey? Scientists reveal the lonely macaque's likely fate as animals in his enclosure continue to reject him

• Climate change could determine the sex of your child: Warmer temperatures are linked to a rise in girls being born, study reveals

• Oura Ring 4 review: I wore a tiny health tracker that looks like expensive jewellery for six weeks - here's what it revealed about my health

• Aliens DO exist - they just haven't visited Earth, NASA veteran claims

• T.Rex ran on his tip-toes! Foot-strike analysis reveals the surprisingly dainty run of the King of the Dinosaurs

• Missing chapter of human history revealed in 40,000-year-old symbols

• Oldest New Testament fragments reveal 2,000-year-old words of Jesus

• Why are animals picking on Punch the monkey? Scientists reveal the tragic truth about the viral macaque who keeps getting rejected

• Urgent warning to all 1.8b iPhone users over calendar hijacking scam: 'Do NOT click'

• How often should you change your toothbrush? Scientist finally settles the debate - so, are you doing it enough?

• Horror as hundreds of dogs are starved and drugged on California's Skid Row while officials stay silent