autostereoscopic image displays provide highly realistic three - dimensional images to one or a plurality of viewers without the need for wearable appliances . in some embodiments , the images are viewed through a beamsplitter , while in other embodiments the viewer observes the images on a display screen . a viewer - tracking system monitors the viewer &# 39 ; s movements and directs each image of a stereopair to the proper eye of the viewer . in some embodiments , the stereoimages are kept independent and separately directed through differential polarization . in other embodiments , this is accomplished through selective intensity modulation .