![The Changing Room Illusion via YouTube [Shared] [Video]](http://welchwrite.com/blog/wp-content/uploads/2021/08/dew-prodile-2021-1.jpg)
![The Changing Room Illusion via YouTube [Shared] [Video]](http://welchwrite.com/blog/wp-content/uploads/2022/10/optical-illusion.jpg)
The Changing Room Illusion is an example of “graduate change blindness,” a phenomenon in which observers are unable to notice changes to the world around them when those changes occur gradually. In virtually all prior cases, gradual change blindness is studied by changing individual objects (e.g., a chimney disappearing or a facial expression shifting). While trying to prepare a novel example of this phenomenon for students, I realized that I could change dozens of items change without observers noticing. Overall, this illusion highlights how people may actually perceive and remember far more of the world around them than they intuitively realize.