Dynamic Illumination for Eye-Tracking

An apparatus comprising:

• a first lens and a second lens;
• a first display device configured to output a first visible light image for viewing by a user through the first lens;
• a second display device configured to output a second visible light image for viewing by the user through the second lens;
• an image capture unit;
• a plurality of light sources configured to illuminate a left eye and a right eye of the user with light after the light passes through the first and second lenses, the light from the plurality of light sources used in tracking a gaze of the user while the user is viewing the first and second visible light images through the first and second lenses;
• a first reflective structure configured to
• reflect the first visible light image output by the first display device through the first lens, and
• pass a first corneal reflection from the right eye to the image capture unit;
• a second reflective structure configured to
• reflect the second visible light image output by the second display device through the second lens, and
• pass a second corneal reflection from the left eye to the image capture unit;
• and
• a controller
• configured to:
• generate at least one of the first corneal reflection or the second corneal reflection using a first one of the plurality of light sources;
• and
• stop light output from the first one of the plurality of light sources if the light output from the first one of the plurality of light sources results in either the first corneal reflection or the second corneal reflection intersecting a fixed reflection that is from either the first lens or the second lens and that is captured by the image capture unit.

A method comprising:

• generating, by a controller, a first bitmap representing reflections in a first image frame captured by an image capture unit within a stereoscopic image viewer;
• generating, by the controller, a second bitmap representing reflections in a second image frame captured by the image capture unit within the stereoscopic image viewer;
• subtracting, by the controller, the second bitmap from the first bitmap to obtain a new bitmap;
• and
• stopping, by the controller, light output from one of a plurality of light sources within the stereoscopic image viewer if all bits in the new bitmap have a same state.