Your brain has a tough job interpreting all of the many sensory inputs to create a full picture of the real world in your mind. 

Because it can't see everything at once and needs a short period of time to process what it actually does see, it uses your past experiences to fill in any blanks. 

Optical illusions exploit this limitation of the brain to trick it into seeing things that are not really there. 

This SciShow video examines eight popular optical illusions and explains why they work the way that they do. 

Check out the video below and let us know your thoughts in the comments!