Illusions occur within our brain's, not our eyes. We perceive a complete pattern and fill in the missing spots. There are many different types of illusions that we've discussed in the Lilienfield text. Some of these included the moon illusion
and the Muller-Lyer illusion
Moon Illusion above
There are many different explanations for why this occurs but none of them have been universally accepted. Some scientists believe it has to do with our atmosphere, but most people dismiss that theory because they say the atmosphere only effects the color.
I believe illusions are important because they definitely have an interest factor and are generally amusing to most people. We definitely see them in every day life without even realizing that we are experiencing an illusion. We basically wrongly perceive something and our brain fills in the missing information to give us the illusion that we are seeing everything that we should be. I for of illusion is a blind sport which is when you reach a certain distance while looking in the mirror where your lens cannot focus properly. Our brains fill in the missing information using the environment around us to fill in the gaps. (192) There are many illusions that use the combination of shapes and colors to make you believe an object is moving when its not. Here is an example of one: Optical Illusion
Illusions are a very interesting aspect of psychology that many people ignore while perceiving one. They don't think about how your brain is actually working during this psychological process. Illusions are just another reason why they human brain is so advanced and adaptive.