RESUMEN
Some studies reported the relationship between near- work activity and progression of myopia. The objective of this study is to investigate a longitudinal changes in refractive errors of the participant's student in entrance exam of the universities [EEU] in educational zones of Mashhad. In this study, 49 students in the final year of high school were randomly chosen and followed longitudinally study using standard objective and subjective refraction methods. Their refractive errors were determined in two succeeding visits; first: before the EEU [October] and second: after EEU [August of the following year]. The data were then statistically analyzed by SPSS. From 49 students [20 boys and 29 girls] the results of this study indicate that after EEU, the amount of myopia [spherical equivalent] increases from-0.088 to-0.357 dioptres [P=0.001] in boys and from -0.085 to-0.365 dioptres in girls [P=0,008]. Amount and type of astigmatism did not change significantly in boys and girls after EEU. These results support the idea that longtime reading and intensive near vision working in short distance relates with increasng the amount of myopia, but it does not correlate with the amount and type of astigmatism