New Delhi, Aug. 6 -- A new optical illusion has taken the internet by storm which is challenging people to spot a hidden number concealed within a pink circle. While the puzzle seems simple at first glance, it is proved to be far more difficult than expected.

Only those with sharp observational skills and laser-like focus are more likely to crack it. The challenge? You have got to spot the hidden number in just 10 seconds.

Also Read: Optical illusion: Only those with 10/10 vision can read this hidden sentence in 22 seconds

These kinds of puzzles are more than just fun; they are a great workout for the brain. According to cognitive experts, such optical illusions test a person's visual perception, concentration power, attention to detai...