In Scholarpedia. 2011.  

"Change blindness" is the failure to detect changes that are easily seen once noticed. Such failures can happen even when the change is large, constantly repeated, and the observer knows that it occurs (e.g. Figure F1). When detected, the change immediately jumps into a viewerÕs awareness with complete clarity. This indicates that change blindness cannot be due to physical factors such as poor visibility, but to mechanisms internal to the observer. It also indicates that even though we have a strong impression that we see everything that happens in front of us, this impression is falseÑthere are limits to what we consciously perceive at any given time.