There are a lot of optical illusions going around the Internet right now: shapes that look like they’re moving but are actually still, images that look like one thing and turn out to be something else, dresses that look one color but are actually another (editors note: it’s white and gold)… There are a ton of illusions that make us see things that aren’t there, but they actually have a simple and logical explanation.
All optical illusions happens when our brain has a hard time deciphering what it sees. When our brain processes information, it goes through a statistical process. In the moment that our senses collect information that isn’t totally clear, our brain tries to correct the information with stored memories from previous experiences.
When our eyes receive vague visual stimuli, the brain gets disoriented and thinks that the image we’re seeing is incomplete and includes movement and depth. This movement isn’t real, it’s actually just created by our brain because it thinks that it didn’t pick up some information.
Optical illusions can be divided into two different groups:
Cognitive optical illusions
This is the most common (and most fun) optical illusion, which happen because of the mistakes that the brain makes when analyzing perspective. It brings together all of the images so that we can’t tell if is one or two figures. For example, a woman’s face, that depending on how you look at it could either be an old lady or a young woman.
Another example of this type of illusion is this image, that can be perceived as either a skull or a couple. Can you see the couple sharing a romantic moment?
In this image of two young women greeting each other, you can see a hidden devil. Did you find it?
Physiological optical illusions
If we look for a long time at a fixed point, the retina is overworked and gets imprinted with a weird post-image, which causes strange visual effects like change in color and shape. If you look at the center of this picture for a few seconds, you’ll see a woman’s face.
If you do the same with this image, you’ll see a hidden religious figure.
Finally, if you look carefully at the black point in the center of the image, you’ll have the sensation that the colors disappear.
Optical illusions are fascinating and they show us that each person has their own perception of things, as the human brain can find different interpretations for the same image. With as much fun as these images are, it’s no surprise that they’re so popular.