The present study attempts to make a link between eye movement measures and reading comprehension (RC) to further examine how reading span (RS) differences contribute to differences in L2 reading performance. The variability of text processing was measured by duration and frequency of fixations using an eye tracker. Thus, it investigates the effects of RS in terms of processing as well as RC performance. To this end, forty-five Korean undergraduate students at an intermediate level participated in the experiment. Four types of eye movements were tracked: first-fixation time (FFT), total-fixation time (TFT), secondfixation time (SFT), and fixation count (FC). The results showed that the high-RS group received higher scores than the low-RS group on the RC test, suggesting a significant role of RS in RC performance. In addition, significant differences between the RS groups were found in TFT and SFT. RC performance is negatively correlated with the TFT and SFT. Due to their limited RS, the low-RS group needed more time for comprehension and left few resources available for integration of meaning in the text. The findings suggest that fast and efficient EMs are closely associated with a better RC performance. The present study shed light on how RS affects the students’ text processing and that, in turn, leads them to different outcomes from the L2 reading comprehension tests.