When you look at this red dot, what do you see? If your eyesight is good enough you'll note a picture hidden inside the circle.
The brain teaser purportedly tests the viewer's vision, with people claiming to see everything from a slim outline to a detailed picture.
Currently trending online, many viewers report being baffled by what the image actually shows.
Given the option to flip the image, the overturned dot reveals a detailed sketch of a horse with a mane, tail, saddle and bridle.
The internet has been awash with puzzles lately including the hunt for answers in an old campsite sketch and challenges to spot the hidden characters in these illustrations by artist Dudolf.
• Scroll down for answers
How did you do?