This study investigated how visual attention differed between students who hold scientific knowledge and those who have misconceptions. We analyzed visual fixations of 98 middle students on problems containing information relevant to scientific knowledge and common misconceptions. It showed that students who acquired scientific concepts paid more attention to appropriate information but took less consideration to irrelevant information. On the contrary, students who held misconceptions fixated more on misleading information but failed to select appropriate information. In addition, the senior students demonstrated more eye fixations on relevant information than their younger peers. These findings reflect that students' conceptual understanding affects the way they evaluate the problem information. Our results also suggest that formal science education improves students' ability to select relevant information and efficiently solve a problem. Studying the visual attention pattern during problem-solving provides implications for the development of effective instructions to promote their ability to solve scientific problems.