Dioptres for a Myopic Eye from a Photo

This paper is inspired from a scene in the movie "Memento" (2000), where the eyeglass prescription for a myopic eye can be estimated since the virtual image of a distant wall seen through the lens and a nearby actor outside the view of the lens are located at the same distance. The estimate illustrates that there are times when the power of physics allows one to arrive at a sophisticated measured result with no equipment. This fascinating example also provides for a nice interdisciplinary connection between physics and medical optics. Due to copyright restrictions on incorporating a movie in class, teachers may use the author's photo and video included here or have their students make similar media with their smartphones.