Unveiling the Dynamics of Eye Movement Patterns in Second Language Reading: The Roles of L2 Proficiency and Exposure

This study investigates how second-language (L2) proficiency and exposure shape online reading behaviour in Chinese learners of English, using eye-tracking to capture moment-to-moment processing. Seventy-nine participants (39 Chinese L2 readers; 40 native English readers) read short English passages while their eye movements were recorded. We examined first fixation duration (FFD), gaze duration (GD), and total reading time (TRT), focusing on word length and frequency at the currently fixated word (N), the previous word (N−1), and the next word (N+1). Chinese participants were grouped through principal component analysis and k-means clustering on IELTS reading scores, vocabulary size, and months in the UK, representing proficiency and exposure, with reading order (Chinese-first vs English-first) controlled for familiarisation. Results showed that advanced learners and those with greater exposure displayed more native-like processing, with shorter fixations and reduced spill-over, while familiarisation through Chinese-first reading further enhanced efficiency. Findings highlight the complementary roles of proficiency, vocabulary, and exposure in shaping L2 reading fluency, with implications for TESOL pedagogy and assessment.