Woman in vanity- or skull?
Hint: move farther a bit from the screen and blink to see the skull or the woman(looking at the mirror)
Do the sides of the square appear to be bent in? Wait, now that is impossible! Believe it or not, they are as straight as they come. If you do not believe us, take astraight edge and see for yourself.
Do these stairs take you anywhere? Yes, they do take you. At the first step.
This is probably the most famous illusion of all time. Almost evryone has seen it. What do you see at your first glance at this illusion? Do you see an old lady or do you see a young woman? they are both there.
Do you see some squares or rectangles? This is really nothing more than a bunch of lines going in every direction, but the way our mind interprets these lines is totally different.