New Delhi, Aug. 18 -- Optical illusion puzzles are a fun and challenging way to test the brain's sharpness. They push your ability to notice the smallest details while working under time pressure. A new puzzle is going viral on the internet, leaving many people scratching their heads. Players need to spot the number 4155 hidden among dozens of 4165s in under 10 seconds. Only those with sharp vision will be able to find the number.

Also read: Optical illusion challenge: Can you find the hidden parrot in 15 seconds?

When you first look at the picture, the grid will look completely filled with the same number, 4165, repeating in every row and column. But if you look carefully, one number among all these is different. Instead of ending with...