What you are "seeing" from your eyeballs is a simulation from the processing power of your brain, a 1/2 second after the fact. eg: Actual Visual (photon off the retina) -> Brain Process (1/2 second) -> Conscious Simulation.

Step 2 can superimpose a false image, (eg: If your brain is a priceless gift, would you trade it in for a refund once you know all the stupid things it does? )