Illusions

So far in Psychology I've learned a lot and retained a little! But one of the things that stuck with me were the lessons on Perception. Discussing the 5 senses, one in particular vision. During class we've went over various situations involving pictures and motion pictures, testing our eyes (vision). Working on Perception and Sensation. And what I've come to find out is that our eyes and brain are very closely related in terms of putting an image together. What we perceive to true physically and mentally. For example if a piece of a pattern was to be missing, and we glanced away from the center of the pattern, our brain would fill in the void with the pattern. It's this false perception our brain gives us to believe the entire pattern is present. When all the time if we were to be looking head onto the picture we would clearly see the void in the pattern. This is because physically head on were looking at the pattern as a whole and can see there is a void present. Mentally now, once we've glanced away our brain establishes the pattern as a whole. It is a visual cue our brain produces. Kind of a blind spot if you will.
http://psychology.about.com/od/sensationandperception/ig/Optical-Illusions/Hermann-Grid-Illusion.htm

This Illusion doesn't have a missing portion of the puzzle. But still gives off the false perception, this filling in the brain does. It's because the brain takes in this pattern and from what it can make up of it when it looks at it from a different angle fills it in from what the surroundings look like.