Optical illusion (visual illusion) — error in visual perception caused by the inaccuracy or inadequacy of unconscious processes correcting the visual image (the moon illusion, incorrect assessment of the lengths of segments, magnitudes of angles or the colours of the depicted object, the illusion of motion, "the illusion of the absence of the object" — banner blindness, etc.), as well as physical causes ("flattened Moon", "broken spoon" in a glass of water). Causes of optical illusions explore how consideration of the physiology of vision and the study of the psychology of visual perception.
ILLUSION
There is an effect of visual perception when the observer consciously or unconsciously gives a factually inaccurate explanation of the observable pattern. It is well known to everyone who watched the fleeing clouds in the sky, sometimes taking the form known visual objects. The same effect can take place under the supervision of the distribution pattern of the shadows of three-dimensional objects at some angles relative to the light sources.
ILLUSIONS OF COLOR PERCEPTION
For about a hundred years it is known that when the retina occurs image consisting of light and dark areas, the light from brightly lit areas as it moves on the dark areas.
THE PERCEPTION OF SIZE
Illusions often lead to completely wrong quantitative estimates of the real geometrical quantities. It turns out that you can be wrong on 25% or more if the eye assessment is not to check with a ruler.
Visual evaluation of geometric real values are very dependent on the nature of the background image. This applies to lengths (illusion Ponzo), areas, radii of curvature. You can show also what is said is true for angles, shapes and so on.
STEREO-ILLUSION
Stereo pair superimposed on the periodic structure (Bela Ulles, Hungary) allow to observe the stereo image as well as the usual stereo pair. Periodic image facilitates the "dilution" of the eye (usually to infinity), after focusing the eye at a distance of several tens of centimeters allows to see stereo.
THE AMES ROOM
Room, invented by Adelbert Ames, Jr. in 1946, is an example of a three-dimensional optical illusion. The room is designed so that when viewed from the front looks normal, with perpendicular walls and ceiling. Actually, the shape of the room is a trapezoid, where the far wall is located at a very acute angle to one.
Have enjoy and train your brain :-)