Optical illusions the devisions of the mind and eye!

A Scintillating grid illusion. Shape position and color contrast converge to produce the illusion of grey blobs at the intersections.Physiological illusions, such as the afterimages following bright lights or adapting stimuli of excessively longer alternating patterns (contingent perceptual aftereffect), are presumed to be the effects on the eyes or brain of excessive stimulation of a specific type - brightness, tilt, color, movement, and so on. The theory is that stimuli have individual dedicated neural paths in the early stages of visual processing, and that repetitive stimulation of only one or a few channels causes a physiological imbalance that alters perception.

Cognitive illusions are assumed to arise by interaction with assumptions about the world, leading to "unconscious inferences", an idea first suggested in the 19th century by Hermann Helmholtz. Cognitive illusions are commonly divided into ambiguous illusions, distorting illusions, paradox illusions, or fiction illusions.

Ambiguous illusions are pictures or objects that elicit a perceptual 'switch' between the alternative interpretations. The Necker cube is a well known example; another instance is the Rubin vase.
Distorting illusions are characterized by distortions of size, length, or curvature. A striking example is the Café wall illusion. Another example is the famous Müller-Lyer illusion.
Paradox illusions are generated by objects that are paradoxical or impossible, such as the Penrose triangle or impossible staircases seen, for example, in M. C. Escher's Ascending and Descending and Waterfall. The triangle is an illusion dependent on a cognitive misunderstanding that adjacent edges must join.
Fictional illusions are defined as the perception of objects that are genuinely not there to all but a single observer, such as those induced by schizophrenia or a hallucinogen. These are more properly called hallucinations.

Perceptual organization

Left - Right Conflict
Duck-Rabbit illusionIn order to make sense of the world it is necessary to organize incoming sensations into information which is meaningful. Gestalt psychologists believe one way this is done is by perceiving individual sensory stimuli as a meaningful whole.[2]

Reversible figure and groundGestalt organization can be used to explain many illusions including the Duck-Rabbit illusion where the image as a whole switches back and forth from being a duck then being a rabbit and why in the figure-ground illusion the figure and ground are reversible.

Kanizsa triangleIn addition, Gestalt theory can be used to explain the illusory contours in the Kanizsa Triangle. A floating white triangle, which does not exist, is seen. The brain has a need to see familiar simple objects and has a tendency to create a "whole" image from individual elements.[2] Gestalt means "whole" in German. However, another explanation of the Kanizsa Triangle is based in evolutionary psychology and the fact that in order to survive it was important to see form and edges. The use of perceptual organization to create meaning out of stimuli is the principle behind other well-known illusions including impossible objects. Our brain makes sense of shapes and symbols putting them together like a jigsaw puzzle. Formulating that which isn't there to that which is believable.( Allen PhD.)

Depth and motion perception
Illusions can be based on an individual's ability to see in three dimensions even through the image hitting the retina is only two dimensional. The Ponzo illusion is an example of an illusion which uses monocular cues of depth perception to fool the eye.

Ponzo IllusionIn the Ponzo illusion the converging parallel lines tell the brain that the image higher in the visual field is further away therefore the brain perceives the image to be larger, although the two images hitting the retina are the same size. The Optical illusion seen in a diorama/false perspective also exploits assumptions based on monocular cues of depth perception. The M. C. Escher painting Waterfall exploits rules of depth and proximity and our understand of the physical world to create an impossible illusion.

Like depth perception, motion perception is responsible for a number of sensory illusions. Film animation is based on the illusion that the brain perceives a series of slightly varied images produced in rapid succession as a moving picture. Likewise, when we are moving, as we would be while riding in a vehicle, stable surrounding objects may appear to move. We may also perceive a large object, like an airplane, to move more slowly, than smaller objects, like a car, although the larger object is actually moving at a faster rate. The Phi phenomenon is yet another example of how the brain perceives motion, which is most often created by blinking lights in close succession.

Great free games 4 ALL!

Well I hope you enjoyed this lens and found some of it intresting or maybe you even learned a thing or too about my hobby. If you have anything you'd like to ask or share just let me know. Please have a look at my other lens and online guides by clicking on links below.

Our Website, Northern Card Chiefs
A great hockey resource!!!

Squidoo Lenses

Sport & Non Sport Collectibles, trading card Fun!
How to Keep Your Trading Card Collection Investment safe!
The New Age of Sports Card Collecting!
A Sulute to Hockeys Lord Stanley's Cup
The Art of Collecting Vintage Hockey Cards Sets
Convert your VHS tapes before its to late
The stars above with the Hubble telescope
Selling Sport Cards on eBay, Listing, Shipping to Packing
Who is Christopher Pike?
Add you hobby lens to our group
Great Mind and Eye Tricks! Cool Optical Illusions

Ebay Guides
The eBay Feedback System and fairness for the Seller!
SellingSport Cards on eBay, Listing, Shipping, Packing

Visit our eBay store
We carry Cards of all sorts from Hockey too Baseball, Non Sports too Fantasy and other cool collectibles. Coins, Buttons, Books and more! Make sure to check out all of our Complete Sets of great non-sport and sport trading cards. And Look for those hard to find Inserts in our Inserts ONLY section and more...

If you would like to shop somewhere other then eBay then check out my store at eCarter the new alternative.

Click here to Get paid to surf, Paid to read emails and more. A list of FREE programs to join!

For Squidoo Lens owners get FREE Traffic to you Lenses as well as your other sites or blogs!



Easyhit4u is a great place to get started