Abstract: A system is mounted within eyewear or headwear to unobtrusively produce and track reference locations on the surface of one or both eyes of an observer. The system utilizes multiple illumination sources and/or multiple cameras to generate and observe glints from multiple directions. The use of multiple illumination sources and cameras can compensate for the complex, three-dimensional geometry of the head and anatomical variations of the head and eye region that occurs among individuals. The system continuously tracks the initial placement and any slippage of eyewear or headwear. In addition, the use of multiple illumination sources and cameras can maintain high-precision, dynamic eye tracking as an eye moves through its full physiological range. Furthermore, illumination sources placed in the normal line-of-sight of the device wearer increase the accuracy of gaze tracking by producing reference vectors that are close to the visual axis of the device wearer.

Abstract: Systems and methods are provided to measure reaction times and/or responses for head, eye, eyelid movements, and/or changes in pupil geometry. The system includes eyewear or headwear including one or more eye-tracking cameras for monitoring the position and geometry of at least one eye and its components of the user, one or more scene cameras for monitoring the user's surroundings, and one or more processors to determine reaction times. Optionally, the system may include one or more of a multi-axis accelerometer to monitor head movements, light sources to trigger visual evoked responses, and/or electronic inputs that may be used to indicate the time of occurrence of external reference events. Measured reaction times and other measurements may be monitored for use in a range of applications. Responses and reaction times may be measured continuously over extended periods, even over a lifetime to measure consequences of the aging process.

Abstract: 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.

Abstract: A scene illumination system is provided that produces spatially uniform or controlled brightness levels for machine vision applications. The system includes a camera, multiple light sources that preferentially illuminate different regions within the camera's field-of-view, and a processing unit coupled to the camera and light sources. Focal regions of the light sources within the camera's field-of-view are sampled to determine average regional brightness and compared to target brightness levels. The processing unit controls the light/sources to increase or decrease illumination levels to converge toward the target brightness levels within the field-of-view. This modulation of the light sources may be repeated with successive video images until target brightness levels are achieved.