AIM: To investigate the prevalence and related factors of visual display terminal(VDT)syndrome in migrant workers caused by using smartphones.

METHODS: From January to October 2014, migrant workers who worked in 10 factories individually in Tangxia Town Dongguan City, were selected by systematic sampling. Every participant was asked to complete the visual display terminal questionnaire and acepted accommodative amplitude determination, tear-film break up time, corneal fluorescein staining, Schirmer I text and so on. The data was analyzed by the SPSS 19.0 software.

RESULTS: Four hundred and sixty-nine people were enrolled(246 males, 223 females). Among them, 384 cases(206 males and 178 females)were diagnosed as the VDT syndrome, the prevalence rate was 81.9%. Compared the prevalence rate in different gender in 40～<50 groups and 50～<60 group, the differences were statistically significant. The difference of gender was not statistically significant in the other age groups. Patients with VDT syndrome considered that watching the video was the most important use of smartphones, preferred accounted in 181 people(43.1%). People without VDT syndrome thought that communicating through WeChat, QQ and some other chat tools was the most important usage, preferred accounted in 33 people(38.8%). The prevalence of visual fatigue in patients with VDT syndrome was 83.9%(322/384). One hundred and ninety-six patients(60.9%)had accommodative amplitude reduction. The 267 patients(69.5%)with VDT syndrome were identified with dry eye. The difference of watching smartphones in bed between people with or without VDT syndrome was not statistically significant. While on reading novels, watching videos, being in dark and shaking space, having daily sport, getting interval in using, the differences were statistically significant. Daily sport and interval were the protective factors for VDT syndrome, the others were risk factors for VDT syndrome.

CONCLUSION:The main factors for VDT syndrome in the migrant workers are reading novels, watching videos, being in dark and shaking space, poor sport and less interval. To get rid of the bad habits in using smartphones, do more sport, take more intervals, moisten the ocular surface are expected to prevent VDT syndrome.