CC children were registered members of the Childhood Cataract Program of the Chinese Ministry of Health (CCPMOH). All of them were diagnosed with CC by two experienced pediatric ophthalmologists based on a comprehensive evaluation of the onset age (within one year after birth), morphological features of lens opacity, family history, and detailed medical records.

NV children were recruited from the Optometry Department of the ZOC as the control group. NV was defined as BCVA ≥0.3 (log MAR) in children between 3-5 years old or BCVA ≥0.15 (log MAR) in children older than 5 years. Children with strabismus and high refractive error (myopia or hyperopia: >6.0 Diopters; astigmatism: >3.0 Diopters) were excluded from NV group.

Differences in age and sex between the CC and NV groups were compared using the independent samples t test and Chi-square test, respectively. Comparisons of abnormal rates between the CC and NV groups were performed using the Chi-square test. Scores on all subscales recorded for the CC group were compared with those of the NV group and the Chinese urban norm using the independent samples t test and one-sample t test, respectively.

The Conners' Parent Rating Scale 48 (CPRS-48) contains 5 evaluating subscales, including the conduct problems, learning problems, psychosomatic, impulsiveness/hyperactivity, and anxiety subscales. A total of 48 items are included in the questionnaire, and each item is scored from 0 to 3 (0 represents the best, 3 represents the worst). The final scores of the 5 subscales are defined as the mean scores of the corresponding items: conduct problems (2+8+14+19+20+21+22+23+27+33+34+39)/12; learning problems (10+25+31+37)/4; psychosomatic (32+41+43+44+48)/5; impulsiveness/hyperactivity (4+5+11+13)/4; anxiety (12+16+24+47)/4; and the hyperactivity index (4+7+11+13+14+25+31+33+37+38)/10. Final scores and the five subscales of the CPRS-48 between two groups were compared.