India, Aug. 12 -- Optical illusions are taking over the internet. A favorite pastime for many, the popularity of brain teasers is on the rise. If you think you are quick at solving viral optical illusions, we have just the challenge to make you feel otherwise. Here is a photo of cats. Although you initially see three black cats, there is a fourth one hidden somewhere in the image. Only 1 out of 20 people can spot it in just ten seconds.

It is fascinating how optical illusions can teach us to think outside the box and pay attention to things easily overlooked. Similarly, in this viral optical illusion, you see three black cats at first glance. However, a fourth companion to the kitties is also present. People with excellent eyes can locat...