© Springer International Publishing AG 2018. This study moves toward improving digital textbooks by using line-of-sight to judge whether the reader is reading a text for the first time. We believe that this information can be used to provide more useful educational materials. For example, when reading a digital textbook a second (or subsequent) time, it might automatically summarize important points. Of the layouts examined, we found no gaze differences between the first and second readings with a screen vertically divided between text and figures. With a scrolling layout, there was a clearly observed difference between first and second readings, with shorter, fewer, and more narrowly focused gazes during the second reading.