Background:Gender is one of the risk factors accounting for the high prevalence of adolescent myopia.Considerable research results have shown that myopia incidence of female is higher than that of male.This study aimed to analyze the correlation between ocular parameters and serum estrogen level and to investigate the vision changes along with estrogen change in menstrual cycle of adolescent females.Methods:A total of 120 young females aged between 15 and 16 years,diagnosed with myopia were recruited.Spherical lens,cylindrical lens,axis,interpupillary distance (IPD),and vision in each tested eye of the same subject were measured by automatic optometry and comprehensive optometry,with repetition of all measurements in the menstrual cycle of the 2nd or 3rd days,14th days,and 282 days,respectively.Serum estradiol (E2) levels were assayed by chemiluminescence immunoassay at the same three times points of the menstrual cycle mentioned above.Results:In young females with myopia,the spherical lens showed a statistically significant difference among all different time in menstrual cycle (all P ＜ 0.0001).The cylindrical lens,axis,and IPD were changed significantly during the menstrual cycle (P ＜ 0.05).The vision of the three different time points in menstrual cycle had a significant difference (x2 =6.35,P =0.042).The vision during the 14th and 28th day was higher compared to that on the 2nd or 3rd days (P =0.021).Serum E2 levels were significantly different at different time points in menstrual cycle (P ＜ 0.05).E2 levels reached its maximum value on the 142 day and the minimum value on the 2nd or 3rd day.Conclusions:In adolescent females,the spherical lens and other related ocular parameters vary sensitively with different levels of E2 in menstrual cycle.Vision in late menstrual stage is significantly higher than that in premenstrual stage.