Background: Examining student attention in physical classrooms is crucial, but it faces challenges due to the lack of accurate monitoring. Constraints posed by device limitations and the design of educational materials impede the integration of eye-tracking technology in these settings. Objectives: This study aims to (1) develop a wearable eye-tracking system specifically designed to monitor students' eye movements and gaze points on the projector screen within a physical classroom setting; (2) explore the impact of instructor gestures (by compare live instruction by an instructor and video-recorded instruction) on student attention and examine the effectiveness of directing students' attention from text to image through instructor intervention. Methods: An innovative wearable eye-tracking system was developed to monitor learners' eye movements within the physical classroom. Twenty-five students participated in the experiment, which included two approaches: classroom lectured by the instructor and by a video presentation. Results and Conclusions: The results indicate that participants exhibit a stronger inclination to allocate additional time to text content than image content when receiving instruction through video presentations with a laser pointer in the physical classroom. This tendency can be attributed to the participants' requirement for longer reading and comprehension time in the absence of an instructor. Additionally, the instructor's gestures and body movements significantly impacted participants' fixation on text slides compared to the image slides. The heatmap analyses support these findings and further indicate that participants focus on the instructor's face rather than other body parts. Takeaways: The wearable eye-tracking technology developed in this study holds promise for future educational research, offering further exploration and analysis opportunities.