In Latin, illudere means to mock or trick, which is the origin of the word illusion.
To give us a sensory experience, our brain fills in information gaps from the eyes.
We call it perception. Optical illusion pictures are one of the easiest brain attention tests.
Optical illusion pictures have also been used by neuroscientists to study reality perception.
Practicing optical illusion puzzles may improve problem-solving and lateral thinking.
Congratulations to those who found the sad emoji; you have the sharpest eyes and highest attention to detail.
Try more optical illusion challenges from our recommended reading below if you liked this one.