Mental Floss

This Unsettling Optical Illusion Will Convince You You're Falling Into a Black Hole

Michele Debczak

The science behind optical illusions has been thoroughly studied, but researchers are still finding new ways to trick our eyes. This image from a recent study takes advantage of our flawed optical system to disturbing effect. You may want to sit down before looking at the picture below—staring at it long enough makes you feel like you're being sucked into a black hole.

Psychologists from Norway and Japan explain how the trippy phenomenon works in their paper published in Frontiers in Human Neuroscience. Like other optical illusions, the picture prompts the brain to fill in information that isn't there. When faced with a black shape surrounded by black dots, we react as if we were moving toward a dark tunnel. The hole at the center of the image appears to expand even though it's a static image. This is a result of our bodies anticipating the transition from light to total darkness.

The study authors presented the illusion in various colors, along with control images containing no obvious patterns, to 50 subjects in the study. When the hole and dots were black against white, 86 percent of participants reported sensing the darkness expanding. Observations of their eye movements showed that the response to the stimuli was physical as well as mental. As they stared at the center of the image, their pupils dilated as though they were entering darkness even though light levels in the room remained the same. This suggests that just the anticipation of a sudden change in light can cause our eyes to react.

If you don't notice anything strange when you stare into the picture, you're not alone—14 percent of the study participants didn't perceive the black hole getting bigger, and the researchers aren't sure why. Maybe you'll have better luck with these award-winning optical illusions.

[h/t Science Alert]