Looks like someone is staring at you, and facing to the right at the same time.
Is the rice floating? Focus on one grain to stop it.
Cross your eyes and out pops a familiar face.
The reason why we are perceiving one color as two different colors is because of the other colors surrounding the stripes. Each eye has six to seven million cones, which are concentrated in a central yellow spot known as the macula. These cones measure color in different wavelengths, where some of which overlap. Our brain then compares by measuring the differences in wavelengths between the colors. When certain colors are combined, the brain can’t process the data from the cones correctly and we get confused.
These turning gears aren’t actually moving.
How many legs does the elephant have, what about feet?
Is it a quaker or a hopper?
Stare at the white columns, then shift your focus on the empty space. What do you see?
These two yellow lines are actually the same size.
It looks like the gray lines between the rows of black and white squares are curved.
Scan left to right, the dots change color from black to white.
If you look at the left end of the fork there are three, but what about the right?
These two blocks are the same color. Put your finger over the line.
Are you seeing gray squares?
These two straight lines are actually the same size. Just remove the arrows.
Is it two parallel lines of arrows pointing in the opposite direction, or men descending to the left?
Do you see old people, or three people?