Kids science optical illusions
Optical Illusions | Optics for Kids
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What is an Optical Illusion?
Optical Illusions can use color, light and patterns to create images that can be deceptive or misleading to our brains. The information gathered by the eye is processed by the brain, creating a perception that in reality, does not match the true image. Perception refers to the interpretation of what we take in through our eyes. Optical illusions occur because our brain is trying to interpret what we see and make sense of the world around us. Optical illusions simply trick our brains into seeing things which may or may not be real.
Try out some of these illusions and discover just how tricky it can be for your brain to accurately interpret the images from your eyes. Click on any of the images below to begin your exploration of optical illusions.
Moiré
Are the pinwheels moving?
Answer: No, the wheels are not turning. The Moiré effect can produce interesting and beautiful geometric patterns.
Light Bulb
Stare closely at this light bulb for 25 seconds. Then immediately stare at a white wall or sheet of paper. What do you see?
Answer: You should see a glowing light bulb!
Elephant Legs
How many legs do I have?
Answer: Four
Teach
In this illusion you can see the word Teach and its reflection. Can you read the reflection too? What does it say?
Answer: Learn
The Animal
How many animals do you see in the image?
Answer: Look closely, you should be able to see a rabbit and a duck.
The Box and the Sphere
Keep your eyes on the dot. Is it in the front or in the back of the cube?
Ask a friend and see if they agree!
Color Blind
What number do you see in the circle?
Answer: You should be able to see the number 26, but people with various degrees of color blindess may only see the 2 or the 6.
Color Illusion
How many colors are present in the image?
Answer: One shade of green and one shade of red! <br /> <br /> It may look as if the two arms of the "X" use different shades of red, but in face the whole "X" only uses a single shade of red. Likewise, only one shade of green is present throughout the image.
Gradients
Which side of inset bar is darker?
Answer: They are both the same shade!
Hermann Grid Illusion
Count all the black dots you can see
Answer: There are no black dots.
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If you focus directly on each dot, you'll see that all of them are white.
Horizontal Lines
Are the horizontal lines sloping or straight?
Answer: All of the lines are straight.<br /> <br /> The black and white blocks are not aligned and thus fool your brain into thinking that the lines are sloping.
Kanizsa Triangle
How many triangles are present in the image?
Answer: There are no triangles.<br /> <br /> In reality there are only 3 V shapes and 3 shapes that look like Pac-Men.
Muller-Lyer Illusion
Take a very close look at the 2 vertical lines. Do you think one line is longer than the other?
Answer: They are the same size! Hard to believe; get out your ruler to measure the lines and see for yourself!
My Wife and My Mother-in-Law
How many figures can you see in the image below?
Answer: If you look closely, you can see both a young and an elderly woman.
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The picture, My Wife and My Mother-in-Law, is a good example of two images existing in one, and was published in 1915 by the cartoonist W.E. Hill.
Snakes
Are the circles moving in the image?
Answer: Look closely, they aren't moving.
Zollner Illusion
Do you think these lines are parallel?
Answer: They are parallel!
Refraction Illusion
Are both arrows pointing the same direction on the paper behind the glass?
Yes! This illusion demonstrations <a href="~/what-is-optics/refraction/">refraction</a>, the bending of light.
Optical Illusions For Kids - All Free and Cool! | Fractus Learning | Brain Illusions | Optical Illusion Pictures | Optical Illusionz | Optical Illusion Images
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ByBryan Bigari Last Updated:
Optical illusions are fun ways to improve kids’ cognitive abilities.
An optical illusion image stimulates problem–solving skills and visual memory recall because the child will want to figure out how it works.
Optical illusions are caused when the brain interprets the object that the eyes see differently. The rods and cones are the optic receptors in the eyes. What the eyes see is transformed into the brain as electric impulses which the brain interprets. The brain tries to make sense of what the eyes see. Optical illusions present something unusual to the brain.
Illusions aren’t hallucinations. An optical illusion is seeing an object differently, whereas a hallucination is viewing an object that isn’t there.
The three types of optical illusions are literal, cognitive, and physiological. A literal illusion is seeing an image as something different than the image or images displayed. Although the images exist, what you see is based on your perception. A cognitive illusion is how the brain interprets something new that wasn’t explained.
It reveals how the mind relates one object to another and what it’s subconsciously thinking. With a physiological illusion, the brain is confused by what the eye sees with light, color, size, movement, and dimension. The brain rectifies its confusion and then interprets what the eye saw, which isn’t physiologically possible.
The first known optical illusion created was about 2500 years ago on the island of Lesbos in Greece. The coin shows the two animals facing each other forms a wolf face facing forward.
Confetti Illusion
How many different colored circles do you see?
Answer
The circles are all the same color. In July 2018, Dr. Novick, University of Texas professor, shared the Confetti illusion on Twitter. The optical illusion is an example of a Munker illusion where surrounding horizontal stripes in different colors influence the color perception of objects.
Image Source
Hermann Grid Optical Illusion
Take a look at this illustration.
How many black dots do you see?
Answer
No, this isn’t an animated GIF. There are no black dots. There are only black blocks and white space. The high contrast presents the eyes the illusion of grey or black dots at the intersections. Focus on the dot, and you’ll see the dots are white.
Animal Optical Illusion
Take a look at this sketch. How many animals do you see?
Answer
Two: a rabbit is looking to the right, and the duck is looking to the left. The duck’s beak is the rabbit’s ears.
The illusion appeared for the first time in a German magazine in 1892. According to American psychologist Joseph Jastrow, the quicker you switch between the two animals, the more creative you are.
Elephant Leg Illusion
How many legs does this unusual elephant have?
Answer
It is a literal optical illusion.
The brain perceives two different images in one. The artist drew one leg with a foot, four legs without feet and four feet without legs.
Kanizsa Triangle Optical Illusion
What patterns do you see? Do you see triangles? Discs?
Answer
Most people see a white triangle facing upwards and the outline of a black triangle downwards with three black discs. The symmetrical image is three black discs missing a triangular part and three pairs of lines. There is no large white triangle in the middle of the page – though I’m sure you see one!
Italian psychologist Gaetano Kanizsa described the illusion. It explains the law of closure where objects grouped seem to be part of a whole. The brain ignores the gaps and perceives the contour lines as a whole.
Color Gradient Optical Illusion
Which side of the inner rectangle is the darkest?
Answer
The bar is the same color..jpg?mode=max)
The optical illusion is lightness perception. The eyes perceive colors differently depending on the color in the background or foreground.
Muller-Lyer Optical Illusion
Observe the two lines with arrowheads on each end. Which line is the longest?
Answer
The lines are the same length. For most people, the line with the fins facing outward seems longer than the line with the spines facing inward. The illusion was created by a German psychologist F.C. Muller Lyar in 1889. Opinions differ on how the perceptual illusion works, whether it has to do with depth, size, or length
Wife or Mother-in-Law Illusion
Who do you see, the wife or the mother-in-law?
Answer
The mother-in-law’s nose is the wife’s jawline. The wife’s necklace is the mother-in-law’s mouth.
British cartoonist William Ely Hill created this brainteaser in 1915.
It’s almost impossible to see the wife and the mother-in-law’s faces at the same time. According to Australian researchers, people tend to see the faces of people of similar ages. Therefore, younger people see the wife and older people see the face of the mother-in-law.
If you can’t see the mother-in-law, focus on the wife’s right ear. If you can’t see the wife, focus on the mother-in-laws left eyelash.
Image Source
Impossible Trident Illusion
How many prongs are in the fork?
Answer
The impossible fork, also known as blivet, shows an object that can’t exist. At the one end, there are two rectangular prongs, and at the other end, it looks like three cylindrical prongs. It was discovered in 1964 when D. H. Shuster noticed an “ambiguous figure of a new kind” in the advertising section of an aviation journal.
Twelve Black Dots Illusion
How many dots do you see at the same time?
Answer
Most people can’t see all 12 dots simultaneously.
The dots in the middle of their vision stay constant. Peripheral vision isn’t as clear. The brain guesses that the continuous pattern of white lines on a grey background continues peripherally and misses the black dots at certain intersections.
Although posted on Twitter and Facebook, the variation of the Hermann Grid was first published in 2000 in a scientific journal SAGE.
Pink or Grey Sneaker Illusion
What color is the sneaker?
Answer
The shoe is pink and white but many people see it as grey. The brain decides a color by considering the colors surrounding the object. Most people probably see the shoe as grey and teal because the brain takes into consideration the colors of the hand holding the shoe. Those who brains see a blue background depicts that the shoe is pink and white.
Zöllner Optical Illusion
Observe the diagonal lines in the image. Are the lines parallel?
Answer
German astrophysicist Johann K.
F. Zöllner discovered this effect in 1760. The parallel diagonal lines intersect with short horizontal and vertical bars. It creates an image where the parallel lines seem to join and separate from each other. Scholars aren’t sure why this happens. It could be the way the brain adjusts angles, or it may be how it perceives depth. The illusion disappears when the colors in the image have equal values of red and green.
Lilac Chaser Illusion
Stare at the plus sign in the middle of the image for twenty seconds or so. What do you see happening in the circles around the +?
Answer
While staring at the + focal point, it seems as if the lilac dots move in a circle that changes to a space moving around the circle of lilac dots. After about 10-20 seconds a green dot appears that runs around the ring.
Vision expert Jeremy Hinton created the lilac disc in 2005. Apparent movement is when a person sees something in one spot and then in another place, and the brain perceives it as a movement.
The green color is the afterimage. When a person stares at a color for a while and looks away, they may see the same color, which is the positive afterimage. Alternatively, they see the negative afterimage, which is the opposing color of the image.
Poggendorff optical Illusion
Observe the three lines on image. Which line does the black line connect to?
Answer
Although it seems as if the black line links with the blue line, it matches the red line. The image is distorted by the brain‘s perception of diagonal lines interacting with horizontal and vertical edges.
In 1860, German physicist Poggendorff received a letter from Johann Zöllner describing the illusion created by the fabric design. Poggendorff noticed the misalignment of the diagonal lines in the fabric design. The illusion is caused when a thin diagonal line is placed behind wider stripes at an angle.
Two Women Illusion
What do you notice about the women in the picture? Which one is shorter than the other?
Answer
The women are the same size – although they seem to be different sizes.
The room appears square but distorts into a trapezoidal shape. The woman at the left is standing closer than the woman to the right, but it seems visually as if they are in the same depth of field. Hence, the one looks taller than the other.
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Ponzo Optical Illusion
Which yellow horizontal line is the longest?
Answer
The two yellow lines are the same length. The upper line seems longer because of the parallel lines converging in the distance. The perspective hypothesis explains the illusion. In three dimensions an object in the distance needs to be larger to appear the same size as a closer object.
Ebbinghaus Optical Illusion
Which of the two orange discs is smaller – the left one or the right one?
Answer
The orange discs are the same size. The illusion was discovered by German psychologist Hermann Ebbinghaus but was popularized in 1901 when published in a textbook by Edward Titchener.
It is a size contrast illusion. The surrounding blue disc sizes influence the perception of the orange disc sizes.
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Hering Optical Illusion
Which way do the vertical lines bend?
Answer
The lines are straight. It seems as if the lines are bending outward due to the false impression of depth created by the radial background. German physiologist Ewald Hering discovered this geometric optical illusion in 1861.
Moon Illusion
Is the moon bigger when seen at the horizon than in the sky?
Answer
It seems as if the moon is more prominent, surrounded by scenery than high in the sky. The reason why the moon seems bigger closer to the horizon is due to depth perception. The trees, building, and surrounding images are the depth cues. In the sky, there aren’t any depth cues to relate to the moon. The color of the moon, atmospheric perspective, and visual factors influence how the moon’s size is perceived.
Stroop Effect Illusion
Which is faster to read the words or ignoring the words but reading the color of each word?
Answer
It’s faster to read the text. J. Ridley Stroop discovered this marvel in 1930. When reading the color instead of the word, the brain receives conflicting messages. The Speed of Processing theory explains the interference because the text reads faster than words. According to the Selective Attention Theory, naming the color requires more attention than reading the text.
Strawberry Illusion
What color are the strawberries?
Answer
The strawberries aren’t red. There are no red pixels in the image; only cyan pixels. Japanese Psychology professor Akiyoshi Kitaoka published the picture on Twitter. The National Eye Institute explains that the brain ‘corrects’ the color when it perceives it in a different color.
Troxler’s Fading Circle Illusion
What happens to the circle when you stare at the dot in center of the ring for about 20 seconds?
Answer
The circle fades and disappears. In 1804, Swiss physician and philosopher Ignaz Troxler used the illusion to demonstrate how efficient the brain functions. The brain filters out unimportant and non-threatening information to focus on what’s important. When staring at the dot, the brain doesn’t receive any new information, and the circle fades into the white background as the brain disposes of unimportant data.
Image Source
Checkerboard Cylinder Shadow Optical Illusion
Take a look at the checkerboard pattern. What color is square A? Square B?
Answer
The two checker squares A and B are the same color. The illusion is created by the way the brain interprets contrasts and shadow.
The brain perceives a light source from the right that casts a shadow on the board. Therefore, square A seems darker than square B, but both are light grey. The checker shadow illusion was published in 1995 by MIT professor of Vision Science, Edwards Adelson.
Question-Answer Optical Illusion
What word(s) do you see in the painting?
Answer
Question and Answer are the two words. John Langdon’s painting is an example of an intentional perceptional illusion. It is a type of steganography where words are hidden in larger scenes. A person tends to perceive the larger picture and often misses the smaller details.
Image Source
Coffer Optical Illusion
How many circles do you see? How many rectangles?
Answer
There are 16 circles. Vision scientist Anthony Norcia form The Infant Laboratory at Smith-Kettlewell was one of the ten finalists in 2016 Best Illusion of the Year Contest with the Coffer Illusion.
The brain identifies grouped objects to form edges and contours. Segmentation cues contradict the interpretation of a series of rectangular coffers with closed boundaries. The horizontal lines can represent a circle or the intersection of rectangles.
Image Source
Author Bio: Bryan Bigari
Bryan Bigari is the current editor of Fractus Learning. As a father of three, Bryan has a passion for helping kids to both excel in school and have fun with friends and parents. He has worked on education issues at the state and federal level, and is looking forward to sharing his first hand education and toy knowledge with you.
Science of Optical Illusion - BBC News Russian Service
image caption,
The black and white stripes on the left side of the picture merge more than on the right side...or does it just seem that way?
A beautiful optical illusion can be a lot of fun and bring a lot of scientific benefits.
Optical illusion specialist Bo Lotto deliberately tricks the human brain to figure out how our mind works.
Bo Lotto is not a magician who is obliged to keep professional secrets, so he willingly shared the results of his research with the BBC.
Sight, hearing, taste, smell and touch - we rely on all these senses, and yet there is a saying that it is better to see once than hear a hundred times: we trust the eyes most of all.
Our brain, which constantly processes the information received by all sense organs and compares it with the picture of the surrounding world created on the basis of experience, is also used to such trust.
This ability is an essential feature of human evolution. But in part, it is also our weakness...
Mystery of the jungle
Image caption,Try to find a predator in this photo
Take, for example, color. Why is it sometimes so important to see a color picture? The following two illustrations clearly demonstrate this need.
Try to find a dangerous predator in the first black and white photograph of the jungle, which is about to jump on you.
Did it work? If not, or even if the search took more than a couple of seconds, then you have already been bitten.
Why does the task look so difficult? Yes, because you see all surfaces only to the extent that they reflect light, there is nothing more for the eye to catch on.
Now look at the same photo, only in color.
Image caption,In color, everything falls into place at once
The panther is well camouflaged in the lower right corner, but you can still see it. And this is due to the fact that you see all the shades of color, and not just evaluate its intensity.
In other words, your brain receives a lot more information, which makes it easier to make decisions.
Color vision allows us to distinguish more similar and different features in the world around us, which at one time was necessary for survival.
The most amazing thing is that when you found a panther in a color picture, you did not even attach importance to how quickly your brain coped with the task, while for computers this still remains an insurmountable obstacle.
Thus, the study of the effect of optical illusions on the brain helps not only specialists in the field of neurology, but also programmers.
Illusion of contrast
Image caption,The identity of the squares is beyond doubt...
Here you can see two physically identical squares. In fact, they are what they are.
Everything would be very simple if our vision were the direct result of the image displayed on the retina.
However, in reality, the process of creating a visual image is much more complicated. Strictly speaking, what we see is not at all what our eye has physically fixed.
That is, certain initial information is processed by our brain in such a way that the resulting picture differs markedly from objective reality.
For example, the display on the retina is two-dimensional, but the world still has three dimensions.
In addition, the picture on the retina is obtained upside down, as in old cameras, but this does not bother us: the brain from infancy is used to compensating for this omission.
image caption,Or is one square lighter than the other?
And now look what happens if you change the background on which the squares are located.
Agree: the squares suddenly began to differ, although nothing happened to them themselves.
A square on a dark background appears lighter than a square on a light background.
This phenomenon is called the illusion of contrast and clearly proves that when it comes to brightness, everything comes down to the context, the environment in which even the simplest subject is viewed.
Cube illusion
Photo caption,Two inserts are indistinguishable in color
In the first picture, you can clearly see that the two inserts are identical in color.
But what happens if we change the context in a special way?
If we are right when we assume that we see only the meaning of the image, then we can easily create a strong optical illusion by changing the meaning of the two inserts.
In a new context, two physically identical inserts suddenly start to look different. Precisely to seem, because they themselves have not changed in the slightest.
Why is this happening?
image caption,Or still one yellow insert. is the other brown?
The information in the picture tells us that the dark brown inset on the top indicates a low reflective surface under bright light, while the bright orange inset on the side is a highly reflective surface in shadow.
You perceive these two surfaces differently just because your brain assigns different meanings to them based on information coming from other parts of the picture.
Illusion of a table
Photo caption, Two completely different tables.
..
Everything that relates to the perception of color also concerns form.
This axiom is true for all objects we observe.
When you look at this image, you are sure you are seeing two tables of different shapes and sizes.
The table on the left looks much longer and narrower than the table on the right.
And now try to believe that the red table is actually the same green one, only rotated by 90 degrees.
The length of the red table is equal to the width of the green one, and vice versa.
Unbelievable, but true. The only difference is at what angle you observe the picture, and also in color, although in this case, believe me, this does not matter.
Image caption,The tables turn out to be the same, though one is red and the other is green, you can't fool anyone... unless you're colorblind?
Why are the two tables so different from each other at a glance?
Yes, because your brain takes a picture from the retina and adjusts it to the information you already have about the tables in general.
In this case, different viewing angles set a certain perspective and depth of vision, and the brain, based on the picture of the surrounding world that has developed in it, automatically concludes that the green table is longer and narrower than the red one.
All this is somewhat frightening, but at the same time it opens up unprecedented perspectives, allowing us to understand that our perception of the illusory world allows us to comprehend the real world.
Autistic children "see" this optical illusion in a unique way
Photo: iflscience com
Optical illusions force our brain to go beyond the usual perception of the world, reconfiguring the way we process, predict and analyze visual stimuli. This requires complex communication and feedback between different areas of the brain, and new research suggests that this process can be reversed in autistic children.
"When we look at an object or picture, our brain uses processes that take into account our experience and contextual information to help anticipate sensory cues, resolve ambiguities, and fill in missing information," , study author Emily Knight explained in a statement. However, previous research has shown that people with autism spectrum disorder (ASD) process these sensory inputs in atypical ways.
For example, last year Knight authored a study that showed that children diagnosed with ASD do not automatically perceive human body language in the same way that children without autism do.
Noting this delay in unconscious processing, researchers began to suspect that the feedback between higher order brain regions and primary sensory regions might be impaired in people with ASD.
Optical illusions are the perfect tool to test this assumption, and Knight and her colleagues used the famous Kanica figure trick to explore their hypothesis.
Named after the Italian psychologist Gaetano Canica, the illusion involves many figures arranged in such a way as to create the contours of another image, such as two human faces that appear to be facing each other, leaving a vase-shaped empty space between them.
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The study authors recruited 60 children, including 29 with ASD, for an experiment in which they were asked to focus on a dot in the middle of a screen while Kanitz's figures appeared in the background. By not directly focusing on these illusions, the participants viewed them passively rather than actively, which gave the researchers the opportunity to study their automatic brain activity in response to these odd numbers.
Using electroencephalography (EEG) to record children's brain wave activity, the authors of the study observed that children with ASD were slower to process Kanishi figures than children without autism.
"This tells us that these children may not be able to predict and fill in visual missing information as well as their peers," says Knight.
Based on this observation, the researchers argue that people with autism appear to have a deficit in “visual feedback processing”, which means that the relationship between areas of sensory input and those involved in the analysis of these signals may be less effective in children with autism.
