Reliable assessment of pupillary dynamics behind closed eyelids remains a central challenge for monitoring brain state in sleep, anesthesia, and unresponsive conditions. In this study we introduce a polarizer-assisted extension of short-wave infrared (SWIR) imaging that enhances contrast and signal fidelity for touchless pupillometry through closed eyes. By optimizing polarizer configurations and image-processing algorithms, we achieve improved signal-to-noise ratio for pupillary light reflex (PLR) measurements and more robust pupil localization and gaze estimation. This approach significantly reduces pupil position dependence and advances the feasibility of accurate closed-eye pupillometry for clinical and research applications.
Polarizer-assisted pupillometry through closed eyelids, overcoming pupil position dependence
