Monitoring Visual Fatigue with Eye Tracking in a Pharmaceutical Packing Area

This study investigates visual fatigue in a real-world pharmaceutical packaging environment, where operators perform repetitive inspection and packing tasks under frequently suboptimal lighting conditions. A human-centered methodology was applied, combining adapted self-report questionnaires with high-frequency eye-tracking data collected via Tobii Pro Glasses 3, alongside lux-level measurements. Key eye movement metrics, such as fixation duration, visit patterns, and pupil diameter, were analyzed within defined work zones (Areas of Interest). Principal Component Analysis was employed to reduce data complexity and uncover latent visual behavior patterns. Results revealed a progressive increase in visual fatigue across the workweek, throughout each shift, and particularly during night shifts, and is strongly associated with inadequate lighting. Notably, tasks involving high physical workload under poor illumination emerged as critical risk scenarios. This integrated approach not only confirmed the presence of visual fatigue but also identified high-risk conditions in the workflow, enabling targeted ergonomic interventions. The findings offer a practical framework for enhancing operator well-being and inspection performance through sensor-based monitoring and environment-specific design improvements, aligned with the goals of Industry 5.0.