Abstract: A head-mounted display may include a display system and an optical system in a housing. The display system may have displays that produce images. Positioners may be used to move the displays relative to the eye positions of a user's eyes. An adjustable optical system may include tunable lenses such as tunable cylindrical liquid crystal lenses. The displays may be viewed through the lenses when the user's eyes are at the eye positions. A sensor may be incorporated into the head-mounted display to measure refractive errors in the user's eyes. The sensor may include waveguides and volume holograms, and a camera for gathering light that has reflected from the retinas of the user's eyes. Viewing comfort may be enhanced by adjusting display positions relative to the eye positions and/or by adjusting lens settings based on the content being presented on the display and/or measured refractive errors.

Abstract: A multi-layer polyolefinic film for the unitization of goods is described. The multi-layer film has a multi-layer structure comprising various polyolefinic compositions, the polyolefinic layers having microcrystalline orientation providing the multi-layer film the ability to shrink in response to heat. The heat shrinkable multi-layer film may be placed over a good or a collection of loosely assembled goods and subjected to heat so that the film shrinks causing the good to be contained by the multi-layer film. The multi-layer film has sufficient clarity so that the good or goods can be visually seen through the film. The heat shrinkable polyolefinic multi-layer films are useful for applications where the loosely assembled goods require containment, but where it is also beneficial for the identity of the goods to not be obscured.