“This is an illusion that’s so good it’s hard to believe it’s an illusion. When the black and white lines disappear, it’s easy to see the rectangles are moving at constant speed. But before that they seem to be taking turns, and pausing when they reach each new line.”
The original illusion image is a gif. I cannot believe it’s a true illusion - it may be a gif animation trick. So I decided to check on the gif animation inside - frame by frame: It’s a true illusion! Amazing!
To clean your doubt. I make a interactive image for this illusion:
- click vertical bars to switch between bars and pure background color;
- click the color block to restart animation
Still hard to believe? The Illusion – Seeing is not always believable! Be careful of what you see!