Below is a silhouette of a lady. The question I have is which direction is she facing? Is she facing toward you or away from you? When we don't have all of the visual details our mind often fills in what is not there.
Did your mind fill in the details for her to be facing you or for her to be facing away from you? The truth is from the silhouette above it is impossible to tell, either answer could be accurate. See the below two penciled in silhouettes to see why.
In this optical illusion can you see the 4 women that make up this man's face?

Click to enlarge picture a see things clearly

In this optical illusion most of us will see a portrait of an old man. However if you look closer you might be able to see a young couple kissing.
Hint: His eyes are the hair of each person in the kiss.

In this optical illusion you see a girl. But if you look carefully you can also see an old woman's face. HINT: Use the girls face as the old woman's nose.

This is one the most famous double image illusions. In this optical illusion you might see an eskimo or an indian. HINT: If you see the eskimo, his left arm is the indian's nose.