In this article we investigated 4th, 6th, and 8th grade students' misconceptions about light, sight, vision, source of light and examined students' conceptual development of these concepts at different grade levels. Data collection was done using five two-tiered test questions with one open-ended question, an interview about concepts and a drawing exercise. Questions were selected from previous studies done by different researchers and were adapted to Turkish. An experienced researcher and a lecturer commented on readability and comprehensibility of the examined test questions. Two-tiered test questions are used to find students explanations. The data frequencies are calculated and formed on tables. Collected data showed some distinguished and similar misconceptions among students' grade levels. These findings showed that light concept is constructed hierarchically in students' minds related to their ages; students' concepts were affected by their daily life experiences. It is suggested that teachers should be aware of students' misconceptions and daily life experiences in order to provide effective teaching. (Contains 14 tables and 5 figures.)