This optical illusion confused viewers and sparked discussion among social media users.

Reddit user shared the illusion, which shows an American flag variation. The flag's vertical lines appear to be slanted, which is unusual.

The flag's white and red boxes are also scattered in a way that can make someone's eyes feel confused.

Reddit user FoxyJnr987 titled the thread: "Flag of United States but it's that weird optical illusion."

FoxyJnr987 explained then that the flag photo was a fake "Cafe Wall Illusion".

FoxyJnr987 stated, "I turned it so that it looks like stripes and made it red the black squares instead."

"The vertical grey lines look sloped when they are straight. It looks better horizontally.

Brain Connection claims that a Cafe Wall Illusion tricks the brain into believing the lines in the image don't run parallel.

It is believed that the illusion of a cafe wall works because of the contrast between the two bricks.

Our brains have a tendency to'spread" dark areas into light areas when interpreting images. This function is known as irradiation. It is this movement that causes false warping effects.

Nevertheless, users weren't able to find any problems with the image. One commentator said: "All of the lines in the flag stand straight, they're not diagonal."

Another wrote, "Thanks for making my eyesight worse,"

Another user wrote, "They don't look diagonal to me. Is my brain broken?"