There are an incredible number of recurrent top-down connections in your vision processing areas. You do not really see what's there in any meaningful way. What you see is heavily conditioned on what other modules of your brain "expect" to see.
Consider foveated vision. The idea that you can actually see what is going on on your desk all at the same time is an illusion.
Consider foveated vision. The idea that you can actually see what is going on on your desk all at the same time is an illusion.