Operating an eye tracker camera according to eye position

A method comprising:

• taking, with a head-mounted device, measurements indicative of positions of an eye of a user (eye positions);
• capturing images of the eye by a head-mounted camera;
• whereby a first range of eye positions trackable from the images is narrower than a second range of eye positions trackable from the measurements;
• calculating eye positions based on the measurements;
• reading the images from the head-mounted camera at a first bitrate when the eye positions fall within the first range;
• refraining from reading the images from the head-mounted camera, or reading the images from the head-mounted camera at a second bitrate that is less than half the first bitrate, when the eye positions fall outside the first range;
• capturing, by a second head-mounted camera, a second set of images of the eye from a different position than the head-mounted camera;
• and
• reading the second set of images from the second head-mounted camera at a higher bitrate when the eye positions fall outside the first range compared to when the eye positions fall within the first range.

A non-transitory computer readable medium storing one or more computer programs configured to cause a processor-based system to execute steps comprising:

• taking, with a head-mounted device, measurements indicative of positions of an eye of a user (eye positions);
• capturing images of the eye by a head-mounted camera;
• whereby a first range of eye positions trackable from the images is narrower than a second range of eye positions trackable from the measurements;
• calculating eye positions based on the measurements;
• reading the images from the head-mounted camera at a first bitrate when the eye positions fall within the first range;
• refraining from reading the images from the head-mounted camera, or reading the images from the head-mounted camera at a second bitrate that is less than half the first bitrate, when the eye positions fall outside the first range;
• capturing, by a second head-mounted camera, a second set of images of the eye from a different position than the head-mounted camera;
• and
• reading the second set of images from the second head-mounted camera at a higher bitrate when the eye positions fall outside the first range compared to when the eye positions fall within the first range.