Woman Or Skull
Illusion #98 : All is Vanity by C. Allan Gilbert. Life, death, and the meaning of existence are intertwined.
An optical illusion can often be the difference between the real world and what the eye and brain together 'see'. The information gathered by the eye is passed to the brain and can be interpreted incorrectly, particularly where sizes are concerned as we are not always good at judging lengths (or colours).