The Participant Calibration Experience

The settings covered in How to Choose Eye Tracking Calibration Settings determine what calibration actually looks and feels like from a participant's side. This page walks through that experience.

Device Requirements

Participants need a webcam capable of at least 1280 by 720 resolution. This is checked automatically before the study starts: a camera that doesn't meet it blocks the participant from starting the study at all, rather than producing lower-quality data, so if you're recruiting participants online, it's worth mentioning this requirement in advance to avoid drop-off at the first step.

Initial Video Feed Calibration

After granting camera access, Labvanced checks that it can see the participant's face clearly before calibration begins. What this looks like depends on the Physiology Toolbox Version:

• Eye Tracking 2.0: this check runs automatically during a short countdown, no action needed from the participant. If their camera or device isn't supported, Labvanced tells them before anything else happens.
• Eye Tracking 1.3 and earlier: the participant sees their own video feed with a tracking overlay and has to manually confirm it looks correct before continuing, or flag it if it doesn't.

The wording participants see on these screens is controlled by Labvanced's Static Strings, which can be edited, and translated if your study needs other languages.

Calibrating the Eye Tracker

What happens next depends on the Physiology Toolbox Version and, for Eye Tracking 2.0, the Calibration Instruction Mode:

• Eye Tracking 2.0, Fast (the default): calibration starts right from the precheck screen shown above, fixate and click the red dot, and the fixation-point sequence below begins immediately, no separate instructions or center-pose screens.
• Eye Tracking 2.0, Detailed, and Eye Tracking 1.3 and earlier: a fuller set of translatable on-screen instructions appears first, covering lighting (constant, from the front, since backlighting washes out the face) and, for this path, asking participants not to wear glasses. The participant then sets a center pose, the reference position used throughout the study (see Virtual Chinrest in How to Choose Eye Tracking Calibration Settings), by aligning a live tracking mesh to a saved target mesh and holding briefly.

From here, both paths continue the same way: the live video feed disappears and a series of fixation points appears instead, one at a time, each marked by a shrinking circle:

The participant looks at each point until it finishes shrinking, then the next point appears. The exact number of points varies by calibration tier, see How to Choose Eye Tracking Calibration Settings. Only the longest tier also asks the participant to slowly tilt and turn their head partway through, as a continuous sweep rather than a held pose, so the system can account for those head positions too; shorter tiers skip this step entirely.

If a participant drifts out of position, Labvanced pauses with an on-screen prompt to realign:

This isn't limited to calibration: the same prompt can appear mid-task, triggered by the Virtual Chinrest settings configured for that task (see Setting Up Eye Tracking in a Task).

Before each subsequent task with eye tracking enabled, a brief recalibration runs again, using whatever recalibration settings were configured for that task (see Setting Up Eye Tracking in a Task).

If the Same Device Calibrated Recently

The setting controlling this is named differently depending on version. Eye Tracking 1.3 and earlier use Allow Calibration Reuse, a single on/off checkbox. Eye Tracking 2.0 replaces it with Calibration Reuse, three options: Never, Test runs only, or Always, and defaults to Test runs only, so real participants in a published study will not see this prompt unless you explicitly set it to Always.

When reuse is allowed and a participant returns on the same device within 8 hours of a previous calibration, at the same window size, Labvanced offers to skip calibration and reuse the saved data instead:

Participants are asked to confirm that their position, lighting, and setup have not changed since the last calibration before this is accepted.

Getting a Good Calibration

Beyond the settings covered elsewhere, a few practical factors affect how well calibration goes for a given participant:

• Position the webcam as close to the monitor as possible (built-in laptop webcams are usually fine). This helps the center pose get set accurately and keeps the whole face in frame.
• Ask participants to remove glasses or face coverings where possible, and make sure their eyes are clearly visible to the camera.
• If a study is loading slowly or eye tracking is not starting, background CPU load is often the cause. Closing other applications and browser tabs, plugging a laptop into power, and setting the computer to a performance power mode all help. A dedicated graphics card, Chrome, and Windows tend to perform most reliably.

Before running a real study, test the calibration process yourself or with a colleague to confirm the settings you have chosen collect the data you expect.

Frequently Asked Questions

Further Reading

How to Choose Eye Tracking Calibration Settings

The settings that shape the experience described on this page.

Setting Up Eye Tracking in a Task

Configure recalibration for individual tasks within a study.

Webcam Eye Tracking Accuracy and Study Design

The evidence behind webcam eye tracking's validated accuracy.