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: The disclosed embodiments include methods and systems for providing tokenized transaction accounts. In one embodiment, a computer-implemented method is provided that may include generating, by one or more processors, a first tokenized transaction account from a first transaction account associated with a first user. The method may also include providing the first tokenized transaction account to a client device associated with the first user for storage in the client device and use in transactions. The method may also include updating the first tokenized transaction account based on one or more conditions and providing the updated first tokenized transaction account to the client device for storage and use in a subsequent transaction.