New Delhi, Aug. 24 -- Optical illusions have always been intriguing and often confuse our brains and eyes, and challenge our perception. One such illusion is going viral online and has left netizens scratching their heads. The challenge is simple: you have to spot the hidden number in a black and white zigzag pattern. At first sight, you will see moving lines, but when you put focus and concentrate, you will clearly see the number. But here is the twist: you have only 30 seconds to find it, and only a few with truly sharp vision can succeed.

The moving zigzag pattern and black-white lines will convince you that it's almost impossible to find the number. But if you put your focus and stare at the image for a few seconds, the numbers will ...