Researchers from Tel Aviv University can monitor changes in pupil size and gaze direction behind closed eyes using touchless infrared imaging. It can help track the depth of sedation, and recognize pain or responsiveness in unconscious patients that may occur after trauma and in intensive care,
https://english.tau.ac.il/research/see-through-closed-eyes
https://www.aftau.org/news_item/closed-eye-imaging-can-track-pain-in-unresponsive-patients/