Epilepsy causes potentially fatal seizures, leading to fear and anxiety among people with epilepsy and caregivers. Real-time seizure detection can help notify caregivers of seizures, helping reduce anxiety. For this purpose, we developed Lampsy, a privacy-preserving video-based seizure detection device embedded within a light fixture. Various Optical Flow methods and optimizations were tested, with the goal of achieving real-time detection on a Raspberry Pi. We achieved a real-time performance of 30 FPS and a sensitivity and specificity of 99.76% ± 0.35 % without calibration. This work extends the state-of-the art by demonstrating real-time video-based seizure detection seamlessly integrated into everyday environments. See more.