Effectiveness of a school-based health education programme in improving myopia awareness, knowledge, attitudes and preventive practices: a pre-post intervention study in Cape Coast, Ghana

Myopia prevalence is rising in sub-Saharan Africa, yet awareness of its causes and preventive behaviours remains inadequate in community and school settings. School-based health education offers an efficient, scalable platform for reaching children and their immediate caregivers simultaneously. A one-group pre-post intervention study with a convergent parallel mixed-methods design was conducted in six basic and junior high schools (three public, three private) in the Cape Coast Metropolis, Ghana. A total of 718 participants (531 students, 75 teachers, 112 parents) completed structured questionnaires at baseline; 679 (94.6%) were reassessed one month after the intervention ended, and 30 participants took part in focus group discussions (FGDs). Paired-samples t-tests evaluated pre-post changes in knowledge, attitude and practice (KAP) scores; binary logistic regression identified predictors of improved awareness; FGD data were analysed thematically and integrated with the quantitative findings. Baseline myopia awareness was 28.6%, rising to 98.4% post-intervention. KAP scores all improved significantly (all p < 0.001): knowledge scores increased by a mean of 3.56 points (t(678) = − 40.75), attitude scores by 0.49 (t(670) = − 19.04), and practice scores by 0.20 (t(675) = − 4.26). Regular adherence to the 20–20-20 rule among students rose from 3.4% to 47.5%, and the proportion spending more than two hours outdoors daily increased from 26.5% to 50.6%. Low pre-intervention knowledge level was the sole significant predictor of differential awareness improvement (B = − 1.366, p = 0.008). FGDs identified the cost of eye care, academic workload and spectacle stigma as persisting barriers that help explain why practice improved less than knowledge. A brief school-based health education intervention produced large improvements in myopia awareness and knowledge, and smaller but statistically significant improvements in attitudes and preventive practices, across all three stakeholder groups. Persisting structural barriers indicate that education should be combined with measures that address cost, outdoor time and spectacle stigma. These findings support integrating myopia-specific education into Ghana's School Health Education Programme and broader African school health frameworks. Pan African Clinical Trials Registry, PACTR202605598700662, registered 29 May 2026. Retrospectively registered.