本研究探討國中生的看電視時間變化與學習成就對於近視度數的影響，以基隆市國中生學習狀況資料庫的四學期追蹤3,487名學生資料，經由單因子重複量數的變異數分析、迴歸分析與潛在成長模式分析顯示：國中生在四學期的放學後看電視時間，不同學期之間呈現波浪狀，七年級與八年級下學期及九年級上學期看電視時間明顯高於八年級上學期。七年級看電視對於近視度數有正向顯著影響，然而四學期看電視時間變化對於近視度數沒有明顯影響。七年級生放學後看電視時間愈多，學習成就愈差；在四學期放學後的看電視時間愈多，學習成就愈不好。國中生的學習成就愈好，近視度數愈高。七年級放學後看電視時間，透過學習成就對近視度數的影響，具有負向的部分中介效果，然而四學期放學後看電視時間變化，透過學習成就對近視度數的影響沒有中介效果。學生看電視時間愈多，學習成就愈差；課業表現愈好，近視度數愈高；然而看電視時間變化對近視度數沒有明顯影響。學校、教師及家長應注意學生看電視時間、課業與近視度數之關係，避免學生課業負擔，使得近視度數增加。

The main purpose of this study is to explore the impact of changes in TV viewing time and academic achievement of junior high school students on the degree of myopia. It tracked the data of 3,487 students in four semesters from the learning status database of junior high school students in Keelung City. Through one-way repeated measure analysis of variance, regression analysis and latent growth model analysis showed that the time spent watching TV after school among junior high school students in the four semesters showed a wave-like pattern between different semesters. The time spent watching TV in the second semester of seventh grade and eighth grade and the first semester of ninth grade was significantly higher than that in the first semester of eighth grade. Watching TV in seventh grade had a positive and significant impact on the degree of myopia. However, changes in TV viewing time in the fourth semester had no significant impact on the degree of myopia. The more time the seventh-grade students spent watching TV after school, the worse their academic performance will be. The more time the fourth-grade students watched TV after school, the worse their academic performance will be. The higher the academic achievement of junior high school students, the higher the degree of myopia. TV viewing time after school in the seventh grade had a negative partial mediating effect through academic achievement on myopia degree. However, TV viewing time after school in the fourth semester had no mediating effect through academic achievement on myopia degree. The more time students watched TV, the worse their academic performance was; the better their academic performance was, the higher their myopia; however, changes in TV viewing time had no significant impact on myopia. Schools, teachers and parents should pay attention to the relationship between students’ TV viewing time, school-work and myopia degree, so as to avoid students’ schoolwork burden, which will increase myopia degree.