This study aims to investigate the effectiveness of the subtitles embedded into either declarative or procedural video on non-native Turkish speakers' understandings of the content. In addition, their perceived difficulties about and eye behaviors during watching the two videos were explored. There were 40 volunteer international students from various departments. Two experiments were designed to observe how participants' retention performance changed according to the content given in the videos. As participants individually watching the videos, their eye behavior was recorded for more objective observations about their fixations on either subtitle or main areas of the screen. In this way, their eye behaviors and their retention performance were compared. The findings showed that there were no significant differences in participants' scores of retention and perceived difficulty regardless of both the video type (declarative vs. procedural) and subtitle existence (subtitled vs. non-subtitled). Moreover, the declarative video was perceived as difficult despite being easy-to-follow. The eye movement data analysis showed that in both the video types, the number of fixations on the subtitle AOI and main AOI were high in a parallel way, but when the participants experienced with procedural video, the percentage of fixations on subtitle area increased.