Fixing Eye-Gaze Calibration and Tracking Problems

Eye-gaze access lets someone control a device by looking at the screen, and small changes in setup can have a big effect on accuracy. If selections are landing in the wrong place or the device seems to ignore the user, work through these checks before assuming the hardware is faulty.

Check the basics first

• Clean the eye tracker. A smudged camera or sensor bar is a surprisingly common cause of poor tracking.
• Check the lighting. Direct sunlight and strong backlighting interfere with infrared eye tracking. Move away from windows or close blinds.
• Check distance and angle. Most trackers work best at roughly 50–70 cm (20–28 in) from the eyes, with the screen squarely in front of the face, not tilted far up or down.
• Check for glasses glare. Reflections off lenses can confuse the tracker; a slight tilt of the screen often clears them.

Recalibrate

Calibration teaches the device how this person’s eyes look as they move. Re-run it whenever the position changes or accuracy drops. On Tobii Dynavox devices, calibration lives under the Gaze Interaction / access-method settings, not inside the page set. Use a calibration target the person finds engaging, and reduce the number of points if a full calibration is too tiring.

Tune dwell and selection settings

• Dwell time: how long the user must look at a button to select it. Increase it if selections fire by accident; decrease it if selecting feels slow and tiring.
• Selection method: dwell, blink, or an external switch each suit different users. If dwell is frustrating, try a switch-activated selection instead.
• Window/area: some devices let you shrink the active gaze area, which can help users who can only reliably look at part of the screen.

If accuracy is good in some screen areas but not others, that usually points to calibration or positioning rather than a broken tracker. Describe what you see in the chat and we can narrow it down.