If you're asking what it does, it doesn't DO anything, it just IS.
If you're asking what it's due TO, that depends on what specific illusion you're talking about. Some of them are due to our expectations, some are due to idiosyncrasies in our physiology or psychology, and some of them are due to actual physical phenomena.
No, it is not an optical illusion.
A mirage is an optical illusion which is caused by atmospheric conditions. This is often due to the refraction of light from the sky by heated air.
yap.. its just an optical illusion
All mirages are optical illusions but all optical illusions are not mirages.
A mirage on the water creates an optical illusion known as a Fata Morgana, where distant objects appear distorted and elevated due to the bending of light rays.
OpTiCaL ILlUsIoN WaZ MaDe fOr ArT AnD FoR tHe InJoyMeNt oF thE PeOpLE
Optical illusion challenges will increase sharpness of your brain. Also the increasing visual literacy is also possible through optical illusion challenges.
An optical illusion that appears to move is called a "kinetic illusion" or "motion illusion." These illusions create the perception of movement due to specific patterns, colors, or arrangements that trick the brain. Common examples include the "Rotating Snakes" illusion and the "Pinna-Brelstaff" illusion, where static images seem to shift or rotate when viewed.
It is in your question already. An illusion will never be real. If it was real then it would be no illusion. Optical illusions are in a way real. They are real optical illusions. We can however not fake an illusion because the illusion is fake from start.
Bored Panda is a great website which offers a number of different optical illusion pictures. You can also find optical illusion pictures from Yahoo! Images.
A mirage is formed when light rays are bent or refracted due to temperature differences in the air. This bending of light creates an optical illusion where distant objects appear distorted or displaced.
The Müller-Lyer illusion is an optical illusion consisting of a stylized arrow.