Three ways to build a tracker.
Each path trades cost and effort for accuracy and freedom of movement. Start where your parts bin already is.
Glasses with a front camera
Mount a small IR camera on an eyeglasses frame pointed at the eye. The most portable, head-mounted approach — walk around while it tracks.
Read the guide → Immersive PATH 02Inside a VR headset
Add eye cameras into a VR headset for foveated rendering, gaze interaction, and research. Fixed geometry makes calibration far more stable.
Read the guide → No hardware PATH 03Webcam head & gaze
Use any ordinary webcam to estimate head pose and rough gaze direction — zero extra hardware, entirely in software. The fastest place to start.
Read the guide →How an eye tracker sees you.
Read it like a scanpath — each fixation is one stage the light and data pass through, in order.
Illuminate
Near-infrared LEDs light the eye. Invisible to the person, but it makes the pupil and reflections pop for the camera.
Capture
An IR-sensitive camera films the eye at speed. In IR the iris flattens out, so the dark pupil stands out sharply.
Detect the pupil
Software thresholds the frame and fits an ellipse to the darkest blob — the pupil — frame after frame.
Find the glint
The LED leaves a bright corneal reflection. The pupil-to-glint vector cancels out small head movement.
Map to gaze
A polynomial or homography maps that vector to a point on the screen or scene — the actual gaze estimate.
Calibrate
Look at a handful of known dots. Those pairs solve the mapping and pull the raw signal into real-world accuracy.
What you'll actually need.
A baseline glasses build. Swap parts freely — the guides list tested alternatives for every line.
A word on infrared safety
Infrared light is invisible, so you can't rely on your eyes to judge exposure. Keep LED power low, follow tested current limits, and read the infrared safety guide before building. Everything here is educational — build at your own risk.
Grounded in open research.
eyetrackers.org is developed alongside working eye-tracking and XR research — not scraped from spec sheets.
Dr. Jason Orlosky
Jason develops open-source software and DIY tutorials for eye tracking, augmented reality, and virtual reality. His tutorials, sample code, and videos at jeoresearch.com are the reference material behind the build paths on this site.