PupEyes: An interactive Python library for eye movement data processing

We present PupEyes, an open-source Python package for preprocessing and visualizing pupil size and fixation data. PupEyes supports data collected from EyeLink and Tobii eye-trackers as well as any generic dataset that conforms to minimal formatting standards. Developed with current best practices, PupEyes provides a comprehensive pupil preprocessing pipeline and interactive tools for data exploration and diagnosis. In addition to pupil size data, PupEyes provides interactive tools for visualizing fixation data, drawing areas of interest (AOIs), and computing AOI-based metrics. PupEyes uses the pandas data structure and can work seamlessly with other data analysis packages within the Python ecosystem. Overall, PupEyes (1) ensures that pupil size data are preprocessed in a principled, transparent, and reproducible manner, (2) helps researchers better understand their data through interactive visualizations, and (3) enables flexible extensions for further analysis tailored to specific research goals. To ensure computational reproducibility, we provide detailed, executable tutorials ( https://pupeyes.readthedocs.io/ ) that allow users to reproduce and modify the code examples in a virtual environment.