Illision n. : The act of dashing or striking against.

Example:
Do cats ever smile, or is it an Illision of a picture from a happy cat?

Taxonomy
illusion, optical illusion, philosophy, the brain, visual illusions, assumptions, truth, falsehood, free encyclopedia, distortion, human senses, Auditory illusions, taste, Maya, Hindu philosophy, stimulus, dummy, hearing voices.

Defination from the web:
... a distortion in the absence of a stimulus, an illusion describes a misinterpretation of a true sensation. ... An optical illusion is always characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. ... Main article: Auditory illusion ...