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: An insulated sink trap cover for a U-shaped sink trap having a vertical pipe connected to the sink drain outlet for protecting a wheelchair bound person from burning his body when using a sink. The insulated sink trap comprises a trough-shaped bottom section integrally formed with a three-sided vertical section to substantially cover the sink trap. The trough-shaped section is adapted to cover the bottom of the U-shaped sink trap, and the vertical section is adapted to cover at least three sides of the vertical pipe section of the sink trap.