what is the meaning of optical illusion?

Answer 1

Human vision is a complex process that is not yet completely understood, despite hundreds of years of study and research. The complex physical process of visualizing something involves the nearly simultaneous interaction of the eyes and the brain through a network of neurons, receptors, and other specialized cells.

The human eye is equipped with a variety of optical elements including the cornea, iris, pupil, a variable-focus lens, and the retina. Together, these elements work to form images of the objects in a person's field of view. When an object is observed, it is first focused through the cornea and lens onto the retina, a multilayered membrane that contains millions of light-sensitive cells that detect the image and translate it into a series of electrical signals. These image capturing receptors of the retina are termed rods and cones, and are connected with the fibers of the optic nerve bundle through a series of specialized cells that coordinate the transmission of the electrical signals to the brain.

In the brain, the optic nerves from both eyes join at the optic chiasma where information from their retinas is correlated. The visual information is then processed through several steps, eventually arriving at the visual cortex, which is located on the lower rear section of each half of the cerebrum.

Rod and Cone cells

Rod cell vision is commonly referred to as twilight vision because in low light levels it enables individuals to distinguish shapes and the relative brightness of objects, but not their colors.

Cone cell vision, on the other hand, enables the ability to see in true color. Cone cells are concentrated in the middle of the retina while the Rod cells are concentrated at the peripheral regions.

Optical Illusions

By understanding the characteristics of the human vision, it is possible to "fool" the brain into seeing something that is not there or to "bend" something that is actually straight or even to affect the "color" sense of the eye. These Optical Illusions are largely based on adjacent elements that affect the primarily subject in view.

Answer 2

Without copying and pasting and - in a nutshell - optical illusions are a research method.

They are a very interesting way of showing where the brain goes beyond the information given by the environment. Basically, it allows to uncover the assumptions made by the brain when computing the visual percept.

Visual Stimulus --> Brain --> Response

An experimenter can control the visual stimulus and measure the response (the illusion). Systematical variation allows to get at the contribution of the brain.

So in essence, optical illusions derive their meaning as tools to study the brain.

Answer 3

An optical illusion is something that the eye percieves to be, but is not always what it really is. Such as a ship at sea being reflected hundreds of miles away in desert environment by heat waves.

Answer 4

Optic is a prefix that always means "eye". So optical means of the eye.
Illusion means what you think it means. A trick of the mind or eye. So maybe somewhat redundant but gets the point across.

Answer 5

It means that you think you see something that is not really there. A common version is to see "water" in the desert; the water is actually a reflection of the sky caused by refraction of the light by the hot air just above the surface.

Answer 6

It means that you are not seeing what you think you are seeing, i.e. you are not perceiving correctly what you are actually looking at

Answer 7

What you see is not what you get.