Change blindness is a psychological phenomenon that occurs when a significant change in a visual scene goes unnoticed by the observer. Examples would include experiments such as the failure to notice changes to a photograph when the changes occurred during a brief visual disruption or failure to notice when an actor in a short film was replaced by a different actor following a camera cut.
"Successful change detection requires ﬁve distinct steps, and failure at any step leads to change blindness:
1. Direct attention to the change location.
2. Encode into memory what was at the target location before the change.
3. Encode what is at the target location after the change.
4. Compare what you represented from the target location before the change to what was there after the change.
5. Consciously recognize the discrepancy."1
Though similar to the phenomenon known as inattentional blindness, change blindness is subtly different. Where inattentional blindness denotes the failure to report a significant item within a visual scene (presence), change blindness is the failure to report a significant changes in a visual scene (transition). Thus the element of change seems to be the defining difference between the two.2
Bellow are some interesting videos which demonstrate change blindness
Here is a link to the original door study which the Derren Brown video above is based on
1. Change blindness and inattentional blindness
Melinda S. Jensen, Richard Yao, Whitney N. Street and Daniel J. Simonshttp://onlinelibrary.wiley.com/doi/10.1002/wcs.130/pdf
2. When Good Observers Go Bad: Change Blindness, Inattentional Blindness, and Visual