1. Lilac Chaser Illusion
Lilac chaser is a visual illusion, also known as the Pac-Man illusion. It consists of 12 lilac (or pink, rose or magenta), blurred discs arranged in a circle (like the numbers on a clock), around a small black, central cross on a grey background. One of the discs disappears briefly (for about 0.1 second), then the next (about 0.125 second later), and the next, and so on, in a clockwise direction When one stares at the cross for about 20 seconds or so, one sees three different things: A gap running around the circle of lilac discs; A green disc running around the circle of lilac discs in place of the gap; The green disc running around on the gray background, with the lilac discs having disappeared in sequences
2. Motion Illusion
The term illusory motion, also known as motion illusion, is used to define the appearance of movement in a static image. This is an optical illusion in which a static image appears to be moving due to the cognitive effects of interacting color contrasts and shape position.
3. The Spinning Dancer illusion
The Spinning Dancer, also known as the silhouette illusion, is a kinetic, bistable optical illusion resembling a pirouetting female dancer. The illusion, created by web designer Nobuyuki Kayahara, involves the apparent direction of motion of the figure. Some observers initially see the figure as spinning clockwise and some counterclockwise. The illusion derives from the lack of visual cues for depth. For instance, her arms could be swinging either closer to the viewer and to the left or farther from the viewer and to the left, and hence with her circling clockwise or counter-clockwise on either her left or right foot. She changes leg because she is facing either towards or away from the observer, there being no surface features on the silhouette to indicate at any point which side of her is presented: the least ambiguous positions are her profiles when she is on either side of her circle, though it’s still not known whether the foreground or background leg is on the floor, and from where she moves indeterminately either on the near or far arc across to the other profile.
4. Vase or Faces Illusion
This drawing exemplifies one of the key aspects of figure-ground organization, edge-assignment and its effect on shape perception. Notice in the faces/vase drawing below, the perceived shape depends critically on the direction in which the border (edge) between the black and white regions is assigned. If the two curvy edges between the black and white regions are assigned inward then the central white region is seen as a vase shape in front of a black background. No faces are perceived in this case. On the other hand, if the edges are assigned outwards, then the two black profile faces are perceived on a white background and no vase shape is perceived.
5. Impossible Object Illusion
An impossible object (also known as an impossible figure or an undecidable figure) is a type of optical illusion consisting of a two-dimensional figure which is instantly and subconsciously interpreted by the visual system as representing a projection of a three-dimensional object although it is not actually possible for such an object to exist (at least not in the form interpreted by the visual system). In most cases the impossibility becomes apparent after viewing the figure for a few seconds. However, the initial impression of a 3D object remains even after it has been contradicted. There are also more subtle examples of impossible objects where the impossibility does not become apparent spontaneously and it is necessary to consciously examine the geometry of the implied object to determine that it is impossible. Impossible objects are of interest to psychologists, mathematicians and artists without falling entirely into any one discipline.
