AIM: To investigate the influencing factors of disequilibrium refractive development in children aged 6-12 years old.

METHODS: A total of 607 children with a mean age of 8.2±1.8 years old from two primary schools in Binhai New Area of Tianjin in December 2019 were selected by cluster sampling for optical biometry measurement(axial length and equivalent corneal power), cycloplegia refractive examination and questionnaire survey.

RESULTS: The childrens'spherical equivalent was -0.11±1.63D, binocular spherical equivalent difference was -0.08±0.64D and absolute value of spherical equivalent difference was 0.41±0.49D. There were 56 children with anisometropia and 551 children without anisometropia. There was no difference in the absolute value of binocular corneal power difference between anisometropia and non-anisometropia group(0.30±0.34D vs 0.27±0.24D, P=0.430). But the absolute value of axial difference was significantly different(0.67±0.39mm vs 0.13±0.13mm, P=0.005). Multivariate linear regression analysis showed that weekly usage time of phones/computers, weekly close work hours, weekly visual fatigue times and habitual reading distance were the influencing factors of refractive imbalance development(the absolute value of binocular spherical equivalent difference). Habitual reading distance and handedness in writing are the influencing factors of the developmental bias of refractive imbalance(binocular spherical equivalent difference).

CONCLUSION: Children aged 6-12 years old who spend more time on phones/computers, and have prolonged close work, more times of visual fatigue and close habitual reading distance may increase the degree of refractive imbalance. Children with right-handed handwriting and severe left or right head deviation have a deeper degree of myopia in the right eye than in the left eye.