Objective To explore the correlations of eye refractive development with ocular biological parameters and physical development parameters in school-age children, and to collect data on children's eye-using behavior and environment by using eyeglass clip Clouclip M2.

Methods The tested students wore wearable device eyeglass clip Clouclip M2 for 7 days of eye-using behavior and environmental monitoring (including 5 working days and 2 rest days). On the eighth day, students were accompanied by their parents to the hospital for obtaining Clouclip M2 monitoring data reports, and they were also conducted with examinations such as eye diopter, eye biological parameters, and physical development parameters. Relationships of children's eye refractive development with physical development parameters, eye biological parameters, eye-using behavior and eye environment were evaluated.

Results There were significant differences in physical development parameters height, body mass and body mass index (BMI) among students in different grades (P < 0.01), but there were no significant differences in eye biological parametersspherical equivalent (SE), axial length (AL), corneal curvature radius (CR), lens thickness (LT), central corneal thickness (CCT) and anterior chamber depth (ACD)among students in different grades (P>0.05). SE was correlated with AL, ACD, LT and CR (P < 0.05), but had no correlations with CCT, height, body mass and BMI (P>0.05). The probability of myopia was higher in individuals with an average time of watching at a close distance ≥300 minutes per day, the longest time of watching at a close distance ≥80 minutes for one time, an average distance of watching at a close range < 33 cm, an average exposure < 8 times per day, light intensity at daytime < 200 lux and light intensity at nighttime < 125 lux.

Conclusion Physical development is not a sensitive indicator affecting the refractive development of eyes in school-age children, and eye-using behavior and environment play important roles in the formation of myopia in children. An average time of watching at a close range≥300 minutes per day, the longest time of watching at a close distance≥80 minutes for one time, distance of watching at a close distance < 33 cm, effective outdoor exposure < 8 times per day, and light intensity at daytime < 200 lux are the risk factors for myopia. Eyeglass clip Clouclip M2 can continuously monitor the eye-using behavior of children and adolescents, and provide reliable methods for guiding clinical pediatric scientific eye use.