What do you see in the image here? While we definitely cannot see without our eyes, nothing would make sense without input from the brain. The brain has two hemispheres, each divided into four lobes. Each lobe is responsible for different functions. The frontal cortex is responsible for decision making and planning; the temporal lobe for language and memory; and the parietal lobe for spatial skills. The occipital lobe is entirely devoted to vision: It is thus the place where visual illusions happen. One way to understand more about illusion system is to look at how we can trick it, that is, to look at how the brain reacts to visual illusions.
See more illusions and don’t try to be smarter than your brain: Just enjoy being tricked!
Sources: http://aplus.com/, http://sharpbrains.com/