Epidemiology of non-strabismic binocular vision anomalies in Africa: a systematic review and meta-analysis

Random-effects meta-analyses were performed in R to calculate pooled prevalence estimates, and heterogeneity was assessed using the <i>I</i>² statistic. The review protocol was prospectively registered with PROSPERO (CRD42025648345).</p> <p>Nine studies from Ghana, Nigeria, and South Africa, including 2,932 participants, met the inclusion criteria. The pooled prevalence of vergence anomalies was 19.19% (95% CI: 13.36–26.80%; six studies), with convergence insufficiency being the most prevalent (9.20%; 95% CI: 4.47–18.00%).

The pooled prevalence of accommodative anomalies was 18.87% (95% CI: 17.27–20.59%; five studies), with accommodative infacility being the most common (9.00%; 95% CI: 5.97–13.35%).</p> <p>Across the included studies, approximately one in five participants met study-specific criteria for accommodative or vergence anomalies. However, because diagnostic criteria and symptom requirements varied and the certainty of evidence was very low, these estimates should be interpreted as indicative rather than definitive population prevalence estimates.

These findings highlight the need for routine binocular vision assessment, standardised diagnostic criteria, and expanded epidemiological research to support evidence-based optometric care in Africa.</p>