The vision system work consists of three main processes. The first is the basic light source, which reflects the objective physical environment, bombards the eye and produces changes in the retina. Followed by the data directly provided by the senses. The third is the brain's data analysis, which involves a specific correspondence between the structure of the current sensory stimulus and the structure of the previous sensory stimulus, or a certain correspondence between specific sensory stimuli and events. Dennett's point of view is that the information that is visually available is less than the information that our subjective impressions make us believe. Our stable visual world may consist of a brief retina image and a rough high-level representation along with a pop-up mechanism to redirect attention. In this extent, the richness of our visual world is just an illusion.