Comparison of optical and video see-through, head-mounted displays

One of the most promising and challenging future uses of head-mounted displays (HMDs) is in applications where virtual environments enhance rather than replace real environments. To obtain an enhanced view of the real environment, the user wears a see-through HMD to see 3D computer-generated objects superimposed on his/her real-world view. This see-through capability can be accomplished using either an optical or a video see-through HMD. We discuss the tradeoffs between optical and video see-through HMDs with respect to technological, perceptual, and human factors issues, and discuss our experience designing, building, using, and testing these HMDs.