Visual Illusions are important to Psychologists who study Sensation and Perception because they offer insight on how visual processing occurs. Understanding how a certain illusion works help psychologists to better understand how sensation leads to perception. I have included several interesting illusions and I am planning on making a continuation of this post.
Ambiguous Pictures: Visual 'Puns' with more than one interpretation. Start with multiple meanings and try to get to one meaning. These images often appear to change between the possible interpretations, but not both at the same time. this is known as Bistable Perception.