AIM: To analyze the vision distribution and its related risk factors of two teenager aviation schools in Western China.

METHODS: The study was a cross-sectional survey. A total of 233 participants were randomly selected from two teenager aviation schools in Western China in November and December of 2017, which were all qualified through the standard of physical examination by Air Force. Distance visual acuity of students was checked and questionnaires about influencing factors of vision were filled voluntarily. Mann-Whitney U rank-sum test and chi-square test were applied for single factor analysis, and Multiple factor Logistic regression analysis was used for the main influence factors of the vision difference.

RESULTS: The proportion of students with less than 0.8 eyesight in school B of Grade 2 and Grade 3 were 18.6% and 45.9%, which was significantly higher than that of 2.6% and 20% of school A. The well-vision distribution in school B of Grade 2 and Grade 3 were lower than that of school A(P<0.05). Single factor analysis showed that school reading and writing time in school B of Grade 2(360min, average: 180-535min)and Grade 3(470min, average: 440-500min)were higher than that of school A(Greade 2: 200min, average: 180-315min; Grade 3: 440min, average: 400-480min; P<0.05); and outdoor activity time of the two grades(Grade 2: 420min, average: 325-516min and Grade 3: 378min, average: 265-515min)were lower than that of school A(Grade 2: 510min, average: 439-681min and Grade 3: 440min, average: 370-601min; P<0.05), and the proportion of students whose mother had a senior high school degree or above in school B was lower than that of school A(P=0.032). Multiple factor Logistic regression analysis showed that reading and writing time was a risk factor for vision loss(OR=1.109, P=0.010)and outdoor activity time was a protective factor(OR=0.986, P=0.001). Mothers' education background, father's educational background, parents' myopia, primary school enrollment age, class time and electronic product using time were not the main factors affecting the vision.

CONCLUSION: More reading and writing time and less outdoor activity time are the main factors for loss of vision, the key point of school myopia prevention needs to coordinate the time between reading, writing and outdoor activity.