If you think that your eyes can never cheat you then think again because optical illusions are made to cheat your eyes. We all believe in seeing is believing philosophy but optical illusions also known as visual illusion is a phenomenon where the visual image is very different from the actual image. An optical illusion is all about the visual data, which is processed by the eyes and the information is sent to the brain but the brains interpret the data in another way and therefore, we see what the brain interprets for us and not exactly what the eyes are looking at.
As per the research done on optical illusions we normally see what our brains want us to see and therefore, designers who create optical illusions are very clear about that. In some of the research cases, people are invited to lie down on the floor and view the sky with different cloud patterns. In such cases, every individual sees a different object shape in the clouds. This is because the brain collects all the information and stores it and when the individual looks up in the sky the brain looks back into the memory gives out a familiar object that matches with the shape of the cloud. Hence, every individual has a completely different object in their minds. Such games are usually called as mind games because it totally depends on how our brains are reacting at that moment instead of the eyes.
There are many kinds of optical illusions like physiological illusions where excessive stimulation of brightness or color is provided to get the optical illusion. However, physiological illusions are just the after images of what we see and therefore, optical illusions like Hermann grid illusion is considered as one of the best examples of it.
Cognitive illusions are also very popular and some of the most popular cognitive illusions are Penrose Stairs and the Necker Cube which works on the misunderstanding of our mind. The pictures are simple when you look at them but because our mind interprets things like it has seen several times before it takes into consideration the same principle, and we see an optical illusion in front of us. Kanizsa Triangle is also one of the important optical illusions that fall under cognitive illusions because the triangle in the picture never actually exists, but we still see it clearly.
Many optical illusions also make use of the color and shades which can force us to think if the colors are same or different. We have been taught that shadows can change the contrast of the color and therefore, our minds think that way. However, the colors and shades in certain optical illusions never change but since our mind it trained to think that shades can change because of shadows we see a change of color on the screen. In the real world, a mirage is the best example of an optical illusion because it is never there. Similarly, if you look at the rail tracks you will see that they meet somewhere in the distance but the fact is that they always remain parallel to each other.