Virtual Reality (VR) and Generative Artificial Intelligence (Gen-AI) are transforming personalized learning, particularly in intangible cultural heritage (ICH) education. However, designing immersive experiences that enhance engagement without overwhelming learners presents a challenge. This study examines the impact of personalized AI narration on user engagement and attention in a VR environment through eye-tracking metrics. In a controlled experiment with 54 participants, we explored three levels of personalization (high, moderate, none) in a Neapolitan pizza-making task, measuring attention and cognitive load through fixation duration, saccade duration, and pupil diameter. Results indicate that high personalization increased engagement by 64.1% over no personalization (p < 0.001). Furthermore, regression analysis reveals specific eye-tracking metrics significantly predict gameplay duration, underscoring eye-tracking's potential to capture real-time engagement. These findings support the use of eye-tracking to inform the development of adaptive VR learning experiences. Future work may integrate subjective assessments to better understand users' underlying motivations.