Optical illusions: Three ways your eyes may deceive you
Optical illusions have fascinated humans since the beginning of time. Sometimes the brain receives information from the eyes that doesn't seem to 'fit.’ That's an optical illusion.
There are three types of optical illusions: literal, physiological and cognitive.
Literal optical illusions
SEOUL, SOUTH KOREA - OCTOBER 3: Visitors view and experience art works at Trick Eye Museum on October 3, 2016 in Seoul, South Korea. (Photo by Zhong Zhenbin/Anadolu Agency/Getty Images)
The term "literal optical illusion" is somewhat mischaracterized because they've been created to confuse the mind. These are the types of illusions created by artists, but it makes then no less fascinating.
Entire museums and exhibits are dedicated to such illusions, including the Trick Eye Museum in Seoul, South Korea has more than and 100 works of mind-bending art.
Floor to ceiling paintings give visitors a 3-D view, making visitors appear to walk on water, over cavernous cliffs, and more. Trick Eye Museum is a new concept of exhibition space where culture and entertainment are combined.
VIENNA, AUSTRIA OCTOBER 16 : A man takes a photo of a woman inside the Head on the Plate Room, an exhibition part of the Museum of Illusions in Vienna (Photo by Omar Marques/Anadolu Agency/Getty Images)
The Museum of Illusions in Vienna, Austria is a playground of 3-D images, sculptures, and holograms.
The art installations are designed to trick the senses and reveal the limits of our imaginations.
In one room, visitors are invited to be photographed with their head on a plate.
Boy poses next to an art work depicting a dinosaur and created in a special 3D-technique by a Chinese-Korean artist group on June 27, 2013, at the exhibition "Du bist die Kunst!" (You are the Art!) at Augustusburg Palace in Augustusburg near Chemnitz
Artwork jumps from the canvass at Augustusburg Palace in Eastern Germany.
Visitors of the exhibit "Du bist die Kunst!" (You are the Art!), back in 2013, were invited to take pictures of themselves interacting with the art and to share the results on social media.
Optical Illusion. (Photo By BSIP/Universal Images Group via Getty Images)
One type of literal illusion made popular by the widespread use of computers to generate graphics are graphics with repeating patters, which appear to move, despite being still images.
More literal optical illusions:
A 'double-painted' property, on which the owner has painted a second view of the facade, creating a disorientating effect for those inspecting the optical illusion in a suburb of Hamburg, Germany, circa 1955. (Photo by Keystone Hamburg/Keystone/Hulton Archive/Getty Images)
Cognitive optical illusions
circa 1950: A doctor at the Headache Clinic in the Montefiore Hospital using the Rorschach personality test to determine whether the patient's headaches have a psychological origin. (Photo by Orlando /Three Lions/Getty Images)
Cognitive optical illusions are simply described as the mind's ability to interpret information, and each person's mind may interpret the same image or object differently.
One common example of cognitive illusion is seeing an image in the shape of a cloud. One person may think a cloud looks like a dog while the person beside them thinks it looks like a fish.
Cognitive optical illusions are used in psychology, specifically in the form of Rorschach tests - where subjects are asked to interpret a smeared blot of ink on a page.
Physiological optical illusions
Physiological optical illusions are considered true optical illusions because the images are not created for the purpose of tricking the eyes and the mind, but they to anyway.
Sometimes physiological optical illusions have explanations based in science. One such illusion is the so-called green flash that appears at sunset.
North America, USA, Florida, Sarasota, Crescent Beach, Siesta Key, Sunset Green Flash. (Photo by: Bernard Friel/Education Images/Universal Images Group via Getty Images)
According to the American Association for the Advancement of Science, conditions must be perfect for a green flash to appear as the sun sets below the horizon.
AAAS says the green flash is a combination of two optical phenomena: a mirage and the dispersion of sunlight.
"As the sun dips below the horizon the light is being dispersed through the earth's atmosphere like a prism. As the light passes through the familiar Roy G. Biv of the spectrum, sometimes a flash of green can be seen for a few seconds."
Read more about the green flash phenomena at https://www.aaas.org/catching-elusive-green-flash.
Man sunning himself during lockdown in Thurloe Square, Kensington, deserted during the Coronavirus pandemic on 23th April 2020 in London, United Kingdom. The government clampdown includes the closure of most shops, bars and theatres throughout the co
Many physiological optical illusions give the viewer the sense that what's in front of them just cannot be. There are several instances of this phenomenon in architecture.
For example, it cannot be that anyone is able to live or work in the homes in Thurloe Suqare, in Kensington, London. They appear impossibly narrow when viewed from the end of the street.
No.5 Thurloe Square is nicknamed the Thin House. It's thought to be one of the narrowest homes in London.
At its narrowest point, the building is said to be 6 feet wide, spanning to 34 feet at its largest. The large north-facing windows are perfect for letting in lots of light, which is great for artists who use the spaces as studios.
A man crosses a street in front of so-called "Flat House" in Moscow on August 10, 2022. - (Photo by Alexander NEMENOV / AFP) (Photo by ALEXANDER NEMENOV/AFP via Getty Images)
Another building that appears to defy logic when viewed from the front corner is Moscow's so-called Flat House.
The building in Russia has a very acute angle on one corners, causing it to appear completely flat.
The Flat House was built in 1915 by Russian architect Vladimir Piotrovich. He built the Flat House along the line of the plot of land. Today, the Flat House serves as residential apartments.
More physiological optical illusions:
A building being renovated and preserved in Spitalfields, East London makes the roadway appear bent along one side. Woman walks past a wall within a wall in Spitalfields, East London. (Photo by In Pictures Ltd./Corbis via Getty Images)