During eye movements our brain selectively blocks the visual processing of the blurred image and we’re entirely unaware of this gap in visual perception. By the end of the day this visual saccadic suppression will have cumulatively resulted in about 40 minutes of blindness.

The phenomenon of saccadic blindness was first described by Erdmann and Dodge in 1898, when it was noticed during unrelated experiments that an observer could never see the motion of their own eyes. This can easily be duplicated by looking into a mirror, and looking from one eye to another. The eyes can never be observed in motion, yet an external observer clearly sees the motion of the eyes.