A simple — yet “freaky” — optical illusion that is making its rounds on the Internet might have some individuals questioning the reliability of their own eyes.

The illusion shows two clock-like objects spinning. When an individual focuses on the right circle, the left appears to be spinning clockwise. However, once the individual focuses on the left circle, the right appears to spin clockwise.

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Image source: John Baez

The illusion appears to have been developed years ago by professor Arthur Shapiro who posted it on his website with an explanation.

According to Shapiro, the illusion contains two components: the ovals and the lines inside the ovals rotating. It thus perplexes viewers because it pits “two sources of information against each other.”

Despite being created in 2008, the illusion gained attention online in late-July after a physicist at the University of California — Riverside posted it online.

“Freaky,” one individual commented on his post.

“This one is really amazing,” echoed another.

(H/T: Daily Mail)

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