Open-source eye-tracking for visual neuroscience (dual Purkinje image)

• OpenIrisDPI is an open-source digital dual Purkinje image (DPI) eye tracker for visual neuroscience.¹
• It enables precise eye-tracking suitable for physiological measurement and experimental methods.^{1 1}

Weekly enrichment (2026-07-20)

• OpenIrisDPI is an open-source plugin for the OpenIris framework implementing digital dual Purkinje image (dDPI) tracking, published in the Journal of Neuroscience Methods (2026).^{1 2}
• It was developed by Ryan Ressmeyer with the Horwitz lab (University of Washington) and Yates lab (UC Berkeley), alongside Jorge Otero-Millan.^{2 3}
• The system tracks the first and fourth Purkinje reflections plus the pupil at 500 Hz on modern consumer-grade CPUs, achieving sub-arcminute precision with proper optical configuration.^{2 3}
• It is described as the first eye tracker to perform pupillography and DPI tracking simultaneously, enabling a direct comparison between pupil–corneal-reflection (P-CR) and DPI signals.^{2 4}
• In macaque recordings, the P-CR method overestimated fixational drift between saccades relative to DPI.^{2 4}
• DPI accuracy was validated against high-density extracellular recordings of neurons in the lateral geniculate nucleus (LGN).^{2 4}
• Compensating for fixational eye movements using DPI signals produced sharper neuronal receptive-field estimates than simultaneously collected P-CR signals.^{2 4}
• The software is released under the GPL-3.0 license on GitHub with build and operation documentation, lowering cost and accessibility barriers versus prior DPI systems and many P-CR systems.³
• BCI/neuroscience implication: precise knowledge of the retinal image improves visual-neuroscience experiments and gaze-based interfaces where eye-tracking quality is critical.²

Footnotes

1. https://www.sciencedirect.com/science/article/pii/S0165027026000233?dgcid=rss_sd_all ↩ ↩² ↩³ ↩⁴

2. https://doi.org/10.1016/j.jneumeth.2026.110693 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

3. https://github.com/ryan-ressmeyer/OpenIrisDPI ↩ ↩² ↩³

4. https://www.biorxiv.org/content/10.1101/2025.04.18.649589v1.full-text ↩ ↩² ↩³ ↩⁴