A famous experiment involves a gorilla passing through a scene that people are observing, focused on something else. Incredibly, many people do not even see the gorilla. Watch this version.
Many convictions have been overturned because DNA or other evidence indicates that eye-witnesses who were absolutely certain that they saw and identified someone could not have been correct. Where does this leave us with regard to confidence in our visual perception, not only with regard to eye-witness testimony, but in life in general? Can we never trust our own eyes, ears, etc.?