After putting the glass on the mantises, researchers show them a series of shapes on a screen that are designed to look 3-D with the glasses on. The goal is to fool "a mantis into believing it's seeing something that's a likely prey object," project researcher Vivek Nityananda told PRI. "Just a black dot on a white screen, or a black square, that moves around in a particular way." This will allow researchers to judge their depth perception and other aspects of their vision. Results from the study could help researchers design 3-D technology for animals, humans, and robots.