Put your brain to the test with these ten optical illusion

Compare your responses to the ones below to understand about what was going on in your brain during each of these illusions:

1. Can you put the fish in the fishbowl? 

Did you notice a different colored fish in the bowl? You've just witnessed an afterimage. The retina of your eyes contains three types of color receptors (cones) that are most sensitive to red, blue, or green light. When you stare at a specific color for an extended period of time, these receptors get "fatigued." When you stare at a different background, the weary receptors do not work as well. As a result, the information from all of the distinct color sensors is out of sync. This produces the color "afterimages."

2. Bezold effect 

All of the smaller squares within the blue and yellow squares are the same hue. They appear different (magenta and orange) because color is perceived differently depending on its relationship to surrounding hues (blue or yellow in this case depending on the outer square).

3. Café Wall Illusion 

The horizontal lines are straight, even though they do not seem straight.  In this illusion, the vertical zigzag patterns disrupt our horizontal perception.

4. Illusory Motion 

The circles do appear to be moving even though they are static. This is due to the cognitive effects of interacting color contrasts and shape position.

5. How many legs does this elephant have? 

Tricky, isn’t it?! This picture is an impossible picture that also contains some subjective contours, such as the Kanizsa Triangle below:

A white triangle (pointing down) can be seen in this figure even though no triangle is actually drawn. This effect is known as a subjective or illusory contour. The contour of the triangle is created by the shapes around it.

6. The Mueller-Lyer Illusion 

The two horizontal lines are the same length, despite the fact that the one at the bottom appears to be longer. Because the eye angle decreases with distance, the brain instinctively sees objects at greater distances to be larger.

In general, lines with inward flaps, such as a building's corner, are the closest points to the overall item. Lines with outward flaps can also be found at a greater distance, such as the farthest corner of a room. As a result of the Mueller-Lyer illusion, the brain perceives the line with outward flaps to be further away than the line with inward flaps. As a result, the brain perceives the line with outward flaps as longer.

7. Hermann grid illusion 

There are not gray dots in this grid. However “ghostlike” gray blobs are perceived at the intersections of the white lines. The gray dots disappear when looking directly at an intersection. This illusion can be explained by a neural process happening in the visual system called lateral inhibition (the capacity of an active neuron to reduce the activity of its neighbors)..

8. The Ebbinghaus Illusion 

The two orange circles are exactly the same size,even though the one on the left seems smaller. This size distortion may be caused by the size of the surrounding circles or by their distance to the center circle..

9. Does Lincoln’s face look normal? 

It seems normal but now, look at it upright: Lincoln’s eyes do not look quite right!

Some neurons in the brain seem specialized in processing faces. Faces are usually seen upright. When presented upside down, the brain no longer recognizes a picture of a face as a face but rather as an object. Neurons processing objects are different from those processing faces and not as specialized. As a consequence these neurons do not respond to face distortions as well. This explains why we miss the weird eyes when the face is inverted..

10. Can you see a baby? 

Another great example of an illusory contour! The baby’s head is on the left, the baby’s feet are against the trunk of the tree on the right.. 


Test your Brain with these 10 Optical Illusions(QUESTIONS)