Objectives: determine prevalence of myopia in children at primary and secondary shool. Method: descriptive cross-sectional study, 2050 school children selected from four schools, presentative for the urban and suburban area of Hai Phong. Identify the prevalence of a visual disability, myopia in primary and elementary school children. Identify the associated factors with myopia as measured lighting in classroom, interviewing children about their study time, watching TV, video games. Result: only 59 percent lighting measured sample meet lighting standards. Prevalence of myopia was found 19.7 percent in school age children. Prevalence of children in urban was higher than in rural area 29.1 percent and 3.0 percent (p 0.05), 29.1 percent and 3.0 percent in secondary school children and primary school children. The myopia children have associated with burden study time, watching TV and video games. Conclusion: prevanlece of myopia in school children was 19.7 percent, increasing with association of burden study time, watching TV and video games.