AimTo study the prevalence of nearpoint vergence anomalies (convergence insufficiency, convergence excess and fusional vergence dysfunction) and association with gender, age groups, grade level and study site (suburban and rural).MethodsThe study design was cross sectional and data was analyzed for 1201 high school students aged 13–19 years who were randomly selected from 13 high schools in uMhlathuze municipality. Of the total sample, 476 (39.5%) were males and 725 (60.5%) were females. The visual functions evaluated included refractive errors, heterophoria, near point of convergence, accommodative functions and fusional vergences. Possible associations between vergence anomalies and demographic variables (gender, age groups, school grade levels and study site) were explored.ResultsPrevalence estimates were 11.8%, 6% and 4.3% for low suspect, high suspect and definite convergence insufficiency, and 1.9% for the pseudo convergence insufficiency. Convergence excess prevalence was 5.6%, and fusional vergence dysfunction was 3.3%. The prevalence of low suspect CI was significantly higher in suburban than in rural participants (p = 0.01), the reverse was the case for pseudoconvergence insufficiency while the prevalence of convergence excess was significantly higher in the younger than in the older age group (p = 0.02). No other category showed any statistically significant associations with vergence anomalies.ConclusionThe prevalence estimates for vergence anomalies in a sample of black high school students in South Africa were relatively low. Only study location and age influenced some vergence anomalies. Identification and referrals are important steps toward diagnosis and treatment for vergence anomalies. Further studies to compare vergence anomalies in various racial populations will be relevant.

This study provides norms for clinical measures which could be used to classify accommodative and vergence parameters for children aged 13-18 years in this population or beyond. Findings should be applied in the context of the measurement techniques and the associated limitations outlined in this report.

Aim: To study the prevalence of myopia among school children in Aba, Nigeria.Methods: This cross-sectional study was conducted in public and private (primary and secondary) schools. A multi-stage random sampling technique was used for selecting participants aged between 8 and 15 years from 12 schools in Aba, Nigeria. Data were analysed for 1197 children who underwent a comprehensive eye examination. The children were divided according to the following criteria: age groups (group 1 [8–11 years] or group 2 [12–15 years]), gender (male or female), level of education (primary or secondary) and type of school (public or private). Myopia was defined as spherical equivalent refraction (SER) ≤ -0.50 D in the poorer eye.Results: The prevalence of myopia was estimated to be 2.7%. Of the 96 children with refractive error, 78.1% were uncorrected. In using logistic regression analysis, risk of developing myopia was associated with older age groups (odds ratio [OR]: 1.20; 95% confidence interval [CI], 0.16–9.11; p < 0.010) and higher level of education (OR: 1.73; 95% CI, 1.05–2.86; p < 0.030). There was no significant difference in myopia prevalence between male and female children (p = 0.89).Conclusion: Although the prevalence of myopia and overall prevalence of refractive error in school children in Aba were low, the high prevalence of uncorrected refractive error is a significant public health problem. An effective and sustainable children’s vision screening programme is needed to prevent visual impairment and blindness.

The prevalence of refractive error in the sample of high school children was relatively low. Myopia was the most prevalent, and findings on its association with age suggest that the prevalence of myopia may be stabilizing at late teenage years.