Question: What and how many numbers are in this puzzle?

An optical illusion has left social media users confused as to what and how many numbers are inside this puzzle.

The illusion picture was posted on the micro-blogging social media application by user @benonwine. It shows a black and white circle that has numbers. The changing pattern has become a puzzle for the netizens.

“DO you see a number?” the question read. “If so, what number?”

The netizens shot their arrows in the dark in the comments section. They also came up with weird reactions to puzzle.

It turned out that the illusion picture is a case of contrast sensitivity.

According to Vision Centre: “Contrast sensitivity is the ability to distinguish between an object and the background behind it. Contrast sensitivity is different from visual acuity, which measures how clear your vision is at a given distance.”

“A contrast sensitivity test measures how well you can tell the difference between light and dark. For this, your doctor will use a different type of chart where the characters fade from black to grey gradually,” it added.