3D movies seem to be all of the rage in the media lately. It has been popularized with the introduction of 3D television for people to enjoy in the comfort of their own homes, and 3D movie production is rising as well. 3D images, however, are not a new concept. When the human eye looks at a still image or any TV show or movie, we can imagine what the image looks like in 3D. Our brain uses information called depth cues in order to interpret an image. These cues include occlusion, shadow, perspective, relative size, and relative height. With these cues, our brain can tell us what object is in front of another, what things are farther away, and the relative size of objects in order to create a "3D" mental image. These however, are monocular cues meaning they are viewed the same with one eyes as they are with both eyes. 3D movies and TV differ because they use binocular disparity. The new 3D movies are filmed with two cameras about eyes' length away. The cameras move in way to mimic eye movement. When the images are projected on to a screen and viewed through the 3D polarized glasses your visual system uses the perspective cues created by the cameras to give the sensation of depth.