A system is provided for identifying reference locations within the environment of a device wearer. The system includes a scene camera mounted on eyewear or headwear coupled to a processing unit. The system may recognize objects with known geometries that occur naturally within the wearer's environment or objects that have been intentionally placed at known locations within the wearer's environment. One or more light sources may be mounted on the headwear that illuminate reflective surfaces at selected times and wavelengths to help identify scene reference locations and glints projected from known locations onto the surface of the eye. The processing unit may control light sources to adjust illumination levels in order to help identify reference locations within the environment and corresponding glints on the surface of the eye. Objects may be identified substantially continuously within video images from scene cameras to provide a continuous data stream of reference locations.