Effectiveness of Vision Screening Program Conducted by Pre-School Teachers

Last reviewed: March 2026

Summary

This randomised controlled study evaluated the effectiveness of a vision screening programme conducted by pre-school teachers in the Klang Valley, Malaysia. The research demonstrated that pre-school teachers who received structured, hands-on training in vision screening techniques could identify children with visual impairment with significantly higher accuracy than untrained teachers, providing evidence that task-shifting of basic vision screening to lay screeners is feasible and effective in the Malaysian context.

Background

Visual impairment in early childhood, if undetected and untreated, can have profound and lasting consequences for child development, educational achievement, and quality of life. The critical period of visual development extends from birth through approximately seven years of age, during which conditions such as amblyopia (lazy eye), strabismus (misalignment of the eyes), and significant refractive errors can cause permanent visual deficits if not corrected in time. Early detection through vision screening is therefore a public health priority.

In Malaysia, the prevalence of visual impairment among pre-school children has been estimated at varying rates across different studies, with refractive errors being the most common cause. Despite the availability of effective treatments (corrective lenses for refractive errors, patching therapy for amblyopia, and surgical correction for significant strabismus), many cases are not detected until children enter formal schooling, by which time the window for optimal intervention may have narrowed or closed.

The primary barrier to universal pre-school vision screening in Malaysia is the limited availability of eye care professionals. Optometrists and ophthalmologists are concentrated in urban centres, and their clinical workloads make it impractical for them to provide screening coverage across all pre-school settings, particularly in rural and semi-rural areas. Task-shifting — the delegation of specific healthcare tasks from specialised professionals to less specialised health workers or trained lay persons — offers a potential solution. Pre-school teachers, who interact with children daily and are trusted by families, represent natural candidates for this role.

Previous international studies have demonstrated that trained teachers can conduct effective vision screening in school-age populations, but less evidence exists for pre-school settings, where children’s younger age and limited verbal ability create additional screening challenges. The present study addressed this gap by evaluating the effectiveness of teacher-conducted vision screening in Malaysian pre-school children aged four to six years.

Methods

The study employed a randomised controlled design. Sixty pre-school teachers from KEMAS (Community Development Department) Tabika and Taska centres across the Klang Valley, Selangor and Kuala Lumpur were recruited and randomly allocated to a Study Group (n = 30) or a Control Group (n = 30).

Teachers in the Study Group received comprehensive participative and hands-on training in vision screening using the KieVision Pre-school Vision Screening Kit. The training programme included theoretical sessions on the importance of vision screening, the types of visual problems detectable through screening, and the interpretation of screening results, followed by practical sessions where teachers practised administering each screening test under supervision. Teachers in the Control Group received only brief verbal instructions on how to use the screening equipment, without structured training or practice opportunities.

Each teacher then conducted vision screening on 15 pre-school children aged four to six years at their respective centres. The screening battery included external eye observation (to detect visible abnormalities such as ptosis, strabismus, or corneal opacities), visual acuity testing (using age-appropriate optotypes), and Hirschberg’s test (to assess ocular alignment). Within two weeks of the teacher screenings, an optometrist independently examined the same children, with the optometrist’s findings serving as the reference standard against which the teachers’ screening accuracy was evaluated.

Key Results

The results demonstrated a striking difference in screening accuracy between the two groups. Teachers in the Study Group, who received comprehensive training, achieved an overall sensitivity of 79% and specificity of 95%. This means that they correctly identified approximately 79% of children with visual impairment (true positives) and correctly cleared approximately 95% of children without visual impairment (true negatives). The Control Group teachers, who received only brief instructions, achieved a much lower sensitivity of 26% while maintaining the same specificity of 95%.

The level of agreement between Study Group teachers and the optometrist was high across all screening components, with Gwet’s AC1 statistic reaching 0.89 or above. This coefficient was chosen over Cohen’s Kappa because of its greater stability when prevalence of the condition is low, which is typical in screening populations.

The dramatic difference in sensitivity between the two groups — 79% versus 26% — while specificity remained constant, indicates that the training intervention specifically improved teachers’ ability to detect true cases of visual impairment without increasing false positive referrals. This is a clinically important finding, as it means that trained teachers can substantially increase the proportion of visually impaired children identified through screening without generating an unmanageable burden of unnecessary referrals to eye care professionals.

Discussion

The results provide strong evidence that pre-school teachers can serve as effective lay vision screeners when given appropriate training, and that the quality of training is the critical determinant of screening accuracy. The training programme evaluated in this study incorporated several elements identified in the vision screening education literature as best practices: a combination of didactic (theoretical) and practical components, hands-on practice with the actual screening equipment, supervised practice sessions with feedback, and clear referral criteria and documentation procedures.

The finding that untrained teachers achieved acceptable specificity but very poor sensitivity has practical significance. It suggests that without training, teachers may adopt an overly conservative approach to screening — clearing most children as normal — which results in few false alarms but many missed cases. Structured training appears to calibrate teachers’ diagnostic thresholds, enabling them to recognise the often subtle signs of visual impairment in young children.

The study used the KieVision Pre-school Vision Screening Kit, a purpose-designed screening tool intended for use by non-eye-care professionals. The availability of user-friendly screening equipment, combined with effective training programmes, creates a scalable model for expanding vision screening coverage to reach the many pre-school children in Malaysia who do not currently have access to professional eye examinations.

Limitations

The study was limited to KEMAS centres in the Klang Valley, an urban and semi-urban region with relatively good access to eye care services. The effectiveness of the teacher screening programme in more remote rural settings, where training logistics are more challenging and follow-up referral pathways less established, requires further evaluation. The study assessed screening accuracy at a single time point and did not evaluate whether teachers’ screening skills are maintained over time without refresher training. The sample of 15 children per teacher, while adequate for validity estimation, limits the precision of individual teacher-level performance estimates.

Significance and Implications

This study demonstrates a practical, evidence-based model for expanding pre-school vision screening coverage in Malaysia through task-shifting to trained teachers. The programme has the potential to reduce the burden of undetected visual impairment among Malaysian pre-school children by leveraging the existing KEMAS pre-school infrastructure and the trust relationship between teachers and families. Implementation at scale would require investment in training programme development and delivery, periodic refresher training to maintain screening quality, and robust referral pathways connecting screened children to eye care professionals for definitive diagnosis and treatment. The model is also potentially applicable to other ASEAN countries facing similar challenges of limited eye care professional workforce and high prevalence of childhood visual impairment.