1. An apparatus for providing environmental information to a visually-impaired user, the apparatus comprising: a portable image sensor configured to be worn by the visually-impaired user and to capture real time image data from an environment of the visually-impaired user; and at least one portable processor device configured to: receive the image data and identify a hand-related trigger in the image data; upon identifying the hand-related trigger, execute a first search in the image data to identify at least a first object from a first category of objects; after initiating the first search, execute a second search in at least one of the image data or results from the first search to identify at least a second object from a second category of objects, differing from the first category of objects; and cause audible feedback to be output to the visually-impaired user, wherein the audible feedback includes information related to at least one of the first and second objects identified in the image data.