Optical illusions

This is definitely one of the best-known optical illusions of all times! What do you see at first glance - an old woman or a young miss? They are both there!
A similar example of ambiguous optical illusions - father and son.
Whole family mind teaser - father with mother and daughter (by G. H. Fischer).
Sigmund Freud and what really on his mind is.
A landscape and the face of a bearded man.
Profile of Salvador Dali and a strange woman.
An old couple - see profiles of faces - is remembering the times when they were young and full of life - see the sitting characters ("Forever Always" by Octavio Ocampo©)
At first sight, what do you see? Do not focus on one region, now look again. You may be surprised (by Joseph Jastrow).
Rabbit and duck one more time.
Swan and squirrel ambiguous image (by G. H. Fischer).
This is one of classic optical illusions - it is called dancing elephant. Try to count the number of his legs (by Roger Shepard).
The tabletops are identical in shape and size! I haven't believed that either, until I measured it myself.
This one is interesting. Children will probably see a group of playing dolphins. But adults see usually something else. It's called Message of Love from the Dolphins (by Sandro Del-Prete).
You probably recognize the face in this painting (it is St. George), but if you look at his hair, you'll see that he is fighting a fire-breathing dragon. It's called "St. George the Dragon Slayer" (by Sandro Del-Prete).
Stare at the dot in the center of the circle and then move your head closer to it. Neat!
Moving circles. (© Akiyoshi Kitaoka: Used with permission.)
Which central circle is bigger? The left one or the right one? Are you sure?
Is the blue wall in the block or on the block? Is it the back wall or the side wall?
Is this a complete cube or just 3 sides of it?
Are the diagonal lines parallel?
Most of the people see a donkey first, but if you look closer you'll find a seal, with its flippers where the donkey's ears are!
Is that a polar bear or a seal on the optical illusion picture below?