Israel’s Blink Energy has developed a tiny device, fitted to one eyelid, that monitors and analyzes blink patterns to detect or diagnose health conditions. E.g., to warn of an imminent epileptic seizure; or if about to fall asleep at the wheel; or to diagnose Parkinson’s disease or sleep disorders.
https://www.israel21c.org/eyelid-wearable-can-predict-and-alert-to-epileptic-seizure/