William Gibson (Neuromancer, Count Zero, and many other fine novels) was further ahead that I even thought. Interesting, but not for me. Thanks for posting that link, kl
"The optics adopted for UP display incorporate Nikon's exclusive adhesion double-layer DOE lens. While most common lenses use refraction to change the direction in which light moves, diffractive optical elements (DOE) use light diffraction. A diffraction grating, shaped like the teeth of a saw with separation of tens to hundreds of micrometers, suppresses chromatic aberration to reproduce crisp and clear VGA images. What's more, this allows for an optical system with a weight of approximately 1/7 that of conventional lens optics (comparison of Nikon designs)."
?