Three-dimensional computer graphics plays a key role in basic research on visual space perception and in numerous applications such as virtual reality. The goal in 3d graphics has been to create the display on a digital display screen that yields the same 2d retinal images as the real 3d scene itself. This can be done stereoscopically by presenting two images on the display screen, one for each eye. The resulting 3d impression can be very compelling. However, the resulting percept is frequently different from that obtained with real scenes and objects. Part, if not all, of the problem can be attributed to inappropriate screen cues that signal the distance to (and shape of' the display screen rather than simulated scene or object. Here we propose to measure the contributions of those screen cues and to develop a novel, multi-focal graphics display system that will circumvent the most problematic of the screen cues. The research effort requires the combined talents of psychophysicists, optical scientists, and computer graphic engineers, so we are requesting funds to put together this collaborative research program. There are four specific aims.1. Measure the influence of digital display cues on perceived 3-dimensionality. We will investigate the contributions of three such cues: a) inappropriate motion parallax during head movements, b) pixelization, and c) inappropriate focus cues.2. Develop an adaptive lens. The requirements are a) high image quality, b) ability to change power by 2 diopters or more, c) frequency response of 180Hz or higher, d) synchronizing lens power changes with the graphic display, and e) small and light enough to be worn by a human observer.3. Develop and evaluate the graphic display algorithm required to simulate focus cues accurately.4. Construct and evaluate the lens and graphical display algorithm. We will test human observers with and without the system in use. We will assess the quality of the resultant in terms of apparent depth, flicker, sharpness, smoothness of motion, and more. We will be particularly interested in using depth-judgment tasks to evaluate the effectiveness of the system in producing more veridical 3d percepts.