1. A system for determining reference locations, comprising: a device configured to be worn on a wearer's head; a scene camera mounted on the device oriented away from the wearer for capturing scene camera images of the environment of the wearer; an eye-tracking camera mounted on the device oriented towards an eye of the wearer for capturing eye-tracking locations of at least one of the wearer's eyes; and one or more processors coupled to the scene camera for determining scene reference locations within the scene camera images and coupled to the eye-tracking camera, the one or more processors using the scene reference locations and the eye-tracking locations to determine locations being viewed by the wearer.