Abstract: A system and method for eye gaze tracking without calibrated cameras, direct measurements of specific users' eye geometries, or requiring the user to visually track a cursor traversing a known trajectory. The preferred embodiment includes two uncalibrated cameras imaging the user's eye and haying on-axis lighting. The cameras capture images of a test pattern in real space as reflected from the user's cornea, which is essentially a convex spherical mirror. The invention then extracts parameters required to define a mathematical mapping between real space and image space, including spherical and perspective transformations. The invention processes subsequent images of objects reflected from the user's eye through the inverse of the mathematical mapping to determine a gaze vector and a point of regard. Alternately, a single calibrated camera may be employed with means for estimating the eye-to-camera distance. A head-mounted embodiment that may include a laser pointer is also described.

Abstract: A system and method for eye gaze tracking without calibrated cameras, direct measurements of specific users' eye geometries, or requiring the user to visually track a cursor traversing a known trajectory. The preferred embodiment includes two uncalibrated cameras imaging the user's eye and having on-axis lighting. The cameras capture images of a test pattern in real space as reflected from the user's cornea, which is essentially a convex spherical mirror. The invention then extracts parameters required to define a mathematical mapping between real space and image space, including spherical and perspective transformations. The invention processes subsequent images of objects reflected from the user's eye through the inverse of the mathematical mapping to determine a gaze vector and a point of regard. Alternately, a single calibrated camera may be employed with means for estimating the eye-to-camera distance. A head-mounted embodiment that may include a laser pointer is also described.

Abstract: A system and method (and signal medium) for interactively displaying information, include a ticker display for displaying items having different views, a tracker for tracking a user's eye movements while observing a first view of information on the ticker display, and a mechanism, based on an output form the tracker, for determining whether a current view has relevance to the user.

Abstract: A method and apparatus analyzes a scene to determine which pupils correspond to which subjects. First, a machine-readable representation of the scene, such as a camera image, is generated. Although more detail may be provided, this representation minimally depicts certain visually perceivable characteristics of multiple pupil candidates corresponding to multiple subjects in the scene. A machine such as a computer then examines various features of the pupil candidates. The features under analysis include (1) visually perceivable characteristics of the pupil candidates at one given time (“spatial cues”), and (2) changes in visually perceivable characteristics of the pupil candidates over a sampling period (“temporal cues”). The spatial and temporal cues may be used to identify associated pupil pairs. Some exemplary spatial cues include interocular distance, shape, height, and color of potentially paired pupils.

Abstract: A method and apparatus determine when a subject is looking at a specific target area by estimating a divergence angle between (1) the direction in which the subject is looking and (2) the direction from the subject directly to the target area. This technique accesses whether the subject is looking at a particular area. The invention may further condition this determination according to the subject's distance from the target area, because there is less tolerance for divergent angles when the subject is farther away. In one embodiment, the divergence angle is estimated using the position of a glint of light in the subject's pupil. The glint is created by a light source located in the target area. If the glint is sufficiently central to the pupil, with the camera and light source being near the target area, the subject is looking at the target area. At long distances, when the glint is not sufficiently discernable from the pupil, another technique may be employed to estimate divergence angle.

Abstract: A system for secure data entry, includes a virtual keypad having a plurality of keys, a mechanism for determining to which virtual key of the keypad a user is looking, and an actuator, operable by the user, for confirming key selection. Another system for secure data entry, includes a virtual keypad having a plurality of keys, an eye tracker for tracking eye movement of a user, and for receiving a coded input from an eye movement of the user gazing upon at least a selected one of the keys of the virtual keypad, and an actuator for being selectively actuated by the user upon confirmation of the coded input by the user.