Optical Illusions

                                       
                                               This is a top-down process Cognitive illusion
It looks like a pencil has throughed two different directions hexagon nuts.It is because when we see it, we just pick up the useful infornations from the image and ignore the useless part. And we know what we expect to see, so our vision has been fooled.


                        Here is the link of the hole viseo,don't be fooled by the illusions,haha
                       http://www.youtube.com/watch?v=QWva0tg-iMk