ThermalEye: Fully Passive Eye Blink Detection on Smart Glasses via Low-Cost Thermal Sensing

Traditional blink detection systems often rely on visible-light cameras, which are sensitive to illumination and raise privacy concerns. To overcome these limitations, we present ThermalEye, a fully passive eye monitoring system integrated into smart glasses that performs robust blink detection using a low-resolution (12 × 16 pixel) infrared thermal array. Our approach features a framework co-designed with both signal processing techniques and a deep learning model to explicitly address the key challenges of this sensing modality: low signal-to-noise ratio (SNR), spatial heterogeneity, and inter- subject variability. Evaluations show that ThermalEye achieves F1-scores of 0.89 and 0.80 at the frame and event levels, highlighting its promise for fatigue monitoring and dry eye assessment.