Eye Health
Prevalence of Visual Acuity Impairment and Its Associated Factors Among Secondary School Students in Beranang, Selangor
Last reviewed: March 2026
Key Findings
- The prevalence of visual acuity impairment among secondary school students in Beranang, Selangor was approximately 25%, a figure higher than comparable studies in other developing countries.
- Refractive error, predominantly myopia, was the leading cause of visual impairment, consistent with the known high prevalence of myopia among East and Southeast Asian populations.
- Many students with visual impairment were undiagnosed and uncorrected, highlighting gaps in school vision screening programmes and access to corrective eyewear.
- The study underscored the importance of comprehensive school-based vision screening and timely referral for ophthalmic care to prevent academic and developmental consequences of uncorrected visual impairment.
Background and Context
Visual impairment among school-age children is a significant public health concern worldwide, with the potential to adversely affect academic performance, psychosocial development, and quality of life. Uncorrected refractive errors — the most common and most easily correctable cause of visual impairment in children — remain a leading cause of preventable disability globally. The World Health Organization has identified uncorrected refractive error as the major and most easily avoidable cause of vision loss, with particular urgency in developing countries where access to eye care services may be limited.
In Malaysia, studies have documented a high prevalence of myopia among school-age children, particularly in urban and suburban populations. A population-based study in Gombak District, Selangor — a suburban area near Kuala Lumpur — found that the prevalence of uncorrected visual impairment (visual acuity ≤20/40 in the better eye) was 17.1% among children aged 7 to 15 years. Notably, myopia prevalence increased sharply from 9.8% in 7-year-olds to 34.4% in 15-year-olds, and more than half of those in need of corrective spectacles were without them.
This study by Aniza and colleagues, published in the Malaysian Journal of Public Health Medicine in 2012, assessed the prevalence and associated factors of visual acuity impairment among secondary school students in Beranang, a semi-rural area in the Hulu Langat district of Selangor.
Study Design and Methods
A cross-sectional study was conducted among secondary school students in Beranang, Selangor. Visual acuity was assessed using standard Snellen chart testing at a distance of 6 metres, with each eye tested separately. Students with visual acuity worse than 6/6 in either eye were further assessed to characterise the type and severity of visual impairment. Additional data on sociodemographic characteristics, visual habits (including near work activities and screen time), family history of visual impairment, and spectacle-wearing history were collected through structured questionnaires.
Visual acuity impairment was defined using established criteria, with students classified by severity ranging from mild impairment to significant visual disability. The study employed statistical analyses to identify factors significantly associated with visual acuity impairment in this population.
Prevalence of Visual Acuity Impairment
The study found that approximately 25% of secondary school students in Beranang had some degree of visual acuity impairment. This prevalence was notably higher than rates reported in comparable studies from several other developing countries. For example, studies from Ethiopia reported prevalences of visual impairment of approximately 5.2–5.8% among school-age children, while studies from Sudan reported 6.4%. The higher prevalence in the Malaysian population was attributed to the well-documented association between East and Southeast Asian ancestry and higher susceptibility to myopia, as well as increasing near-work demands associated with modern educational practices.
Among students with visual impairment, refractive error — predominantly myopia — was the leading cause, consistent with the pattern observed in other Malaysian and regional studies. A significant proportion of affected students were found to be undiagnosed, uncorrected, or inadequately corrected, indicating gaps in both detection and treatment of visual impairment in this school-age population.
Associated Factors
Several factors were found to be associated with visual acuity impairment among the secondary school students. Older age was associated with higher prevalence, reflecting the well-documented progressive nature of myopia during the school years. Female students showed a slightly higher prevalence compared to male students, consistent with findings from other Malaysian studies. Parental history of visual impairment was a significant risk factor, reflecting the known genetic contribution to myopia susceptibility.
Environmental and behavioural factors, including excessive near-work activities (such as reading and studying at close range), prolonged screen exposure, and limited outdoor activity, were also explored as potential contributors. These factors have been increasingly recognised in the literature as modifiable risk factors for myopia development and progression in children.
Implications for School Health Programmes
The findings underscored the critical importance of effective school-based vision screening programmes in Malaysia. While the Malaysian Ministry of Health operates a formal government school vision screening programme, the high prevalence of undetected and uncorrected visual impairment found in this study suggested that existing screening efforts may be insufficient in frequency, coverage, or follow-up effectiveness. Strengthening school vision screening through more frequent assessments, use of validated screening tools, and robust referral pathways to ophthalmic services could significantly reduce the burden of uncorrected visual impairment.
Ensuring that students identified with visual impairment have access to affordable corrective eyewear is equally important. Financial barriers to obtaining spectacles remain a concern for some Malaysian families, and programmes that provide subsidised or free spectacles to students in need could complement screening efforts to improve visual outcomes.
Limitations
The study was limited to secondary school students in a single semi-rural area of Selangor, and findings may not be directly generalisable to other populations or settings. The cross-sectional design did not allow for assessment of temporal trends or progression of visual impairment over time. Vision testing was conducted using Snellen chart methodology, which, while standard and practical for community-based screening, may not capture the full range of visual function deficits. The study did not include cycloplegic refraction, which would have provided more precise characterisation of refractive error types.
Significance for Malaysian Public Health
This study has been widely cited in the international literature on visual impairment among school-age children, reflecting its contribution to understanding the epidemiology of myopia and visual impairment in Southeast Asian populations. The findings provided evidence supporting calls for strengthened vision screening programmes, improved access to corrective eye care, and research into environmental interventions — such as increasing outdoor time — that may help prevent or slow myopia progression in Malaysian school children.
Aniza I, Azmawati MN, Jamsiah M, Idayu BI, Mae Lynn CB. Prevalence of visual acuity impairment and its associated factors among secondary school students in Beranang, Selangor. Malaysian Journal of Public Health Medicine. 2012;12(1):39–44.