New calibration-free gaze tracking system for mice using corneal reflections
Researchers developed an open-source eye tracking system for head-fixed mice that eliminates the need for physical calibration procedures by using multiple LED fiducials and geometric modeling. The method achieves accuracy below 1 degree across the typical range of mouse eye movements and costs approximately $2,000-2,700 USD. This advancement could make precise gaze tracking more accessible to neuroscience laboratories that previously relied on uncalibrated methods.
A new corneal-reflection eye tracking system for mice eliminates the complex calibration procedures that have limited adoption of precise gaze tracking in neuroscience labs. The method uses a geometric model that recovers gaze angles from pupil and corneal reflection displacements, leveraging multiple stationary LED fiducials as reference points rather than requiring physical camera rotation or motorized stages. Validation against a rotary-encoder-controlled artificial eye demonstrated mean absolute errors below 1 degree across a ±20 degree working range, with correlations exceeding 0.998 to ground truth. The system includes an integrated software pipeline for pupil detection, 3D geometry definition, and gaze computation with blink detection and artifact correction. When applied to neural recordings from mouse visual cortex, the gaze-corrected stimulus reconstruction produced sharper receptive field estimates with improved signal-to-noise ratios compared to uncorrected data.
What's missing
The study does not discuss potential limitations in tracking eye movements during non-head-fixed conditions, generalizability to other rodent species beyond mice, or comparison of computational processing time relative to existing methods. The paper also does not address how the system performs with naturally occurring eye movements of varying speeds or during different behavioral states.
What different sources said
- bioRxivCenter
Single-camera, calibration-free gaze estimation using corneal reflections
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