"Big" me. "Little" me. Watch these two versions of me--which are really the same size--explain why I appear petite in one place on screen and large in another. The reason, in short, is that I have been trapped in a clever visual illusion, one invented 78 years ago by American opthalmologist Adelbert Ames Jr. In the HBO movie "Temple Grandin," the main character (Grandin) recreates the same illusion for a class assignment. Watch the scene here. The video below deconstructs the trick that Ames and Grandin play on our eyes.

For more about perceptions that do not match reality, see the story "Re-creating the Real World" by Bruce Hood in the September/October 2012 Scientific American Mind.