The Ponzo effect: The Ponzo effect was first shown by the Italian psychologist Mario Ponzo in 1991. The reason the top horizontal line looks longer is because we view the scene while using linear perspective at the same time. Since the vertical parallel lines seem to move closer together as they move further away, we tend to imagine the top line as being further off in the distance. A line in the distance would need to be longer in order for it to seem like the same size as a closer line, so the top far line is seen as being longer than the bottom near line, despite both lines being equal in size. The Moon illusion is very similar to the Ponzo effect. The Moon illusion is an optical illusion which makes the moon look bigger near the horizon than it does higher up in the sky. Some researchers believe that the Moon illusion is an example of the Ponzo effect, with trees and houses playing the role of Ponzo effect’s converging lines. In the three dimensional world, an object located farther away would have to be larger than a nearby object for both to produce retinal images of the same size. This explanation is called the perspective hypothesis. The Ponzo effect can be tested in the following way: Have five control trials and five experimental trials. For the experimental trials, the converging lines that create the illusion the lines are the same length will be used. For the control trials, the background will be plain. The data for the experimental and control