Urban Peruvian Students Show Double Visual Impairment Rates

A cross-sectional comparative study conducted in Peru’s Amazonas region found that secondary school students in urban areas experienced twice the prevalence of visual impairment compared to their rural counterparts. The research, published in Frontiers in Health Services, assessed 243 students from one rural and one urban public school, revealing a significant disparity in visual acuity that persisted even after adjusting for age and sex. This finding highlights a distinct territorial gap in adolescent eye health within a geographically diverse region of the country.

The study aimed to compare visual acuity levels among adolescents attending rural and urban educational institutions, a distinction that had not been thoroughly examined in this specific region. Visual acuity plays a critical role in adolescent learning, affecting reading, attention, and academic performance. When visual impairment goes unnoticed, it can lead to unrecognized difficulties that impact a student’s safety and interaction with the educational environment. The researchers sought to provide evidence to strengthen school-based vision screening and inform context-specific preventive interventions in the Amazonas region.

Participants were selected through stratified probability sampling from a population of 409 students enrolled in the 2025 academic year. The final sample consisted of 243 students, with 65 from the rural institution and 178 from the urban institution. The rural school was located in a sparsely populated community approximately one hour from Bagua Grande, accessible primarily via unpaved roads, while the urban school was situated in Chachapoyas, offering greater proximity to healthcare services. This contrast in location, accessibility, and availability of health services allowed for a direct comparison of visual acuity across two distinct contexts.

Visual acuity was assessed monocularly using a Snellen chart at a distance of three meters under adequate lighting conditions. None of the students wore spectacles during the assessment, meaning all measurements represented presenting visual acuity without optical correction. The results were categorized according to criteria established by the Peruvian Ministry of Health and the International Classification of Diseases, defining normal vision as 20/20 to 20/30, mild impairment as 20/40 to 20/70, moderate impairment as less than 20/70 to 20/200, and severe impairment as less than 20/200 to 20/400. Overall visual acuity was defined by the performance of the worse eye, a method that prevents unilateral or asymmetric alterations from going unnoticed.

The results indicated that 66.7% of the students had normal vision, while 24.7% had mild visual impairment, 7.0% had moderate visual impairment, and 1.6% had severe visual impairment. When analyzing the prevalence of visual impairment based on the worse eye, 33.3% of students were affected. Using the better eye, as recommended by the World Health Organization, the prevalence was 24.7%. The study found that visual acuity was significantly associated with school location, grade level, and age, but not with sex. These associations suggest that the distribution of visual acuity levels varies across different demographic and academic groups within the student population.

The most striking finding was the difference in visual impairment prevalence between the two school settings. Based on the worse eye, 38.8% of students in the urban school had visual impairment, compared to only 18.5% in the rural school. This difference was statistically significant, with a prevalence ratio of 2.10, indicating that urban students had more than twice the prevalence of visual impairment as rural students. When stratified by sex and age group, the prevalence remained higher in the urban school in every subgroup, although the difference reached statistical significance only among males and students aged 15 to 18 years.

To determine whether school location was associated with visual impairment independently of other factors, the researchers used a Poisson regression model with robust variance, adjusting for age and sex. In this multivariable model, school location was the only factor independently associated with visual impairment. The adjusted prevalence ratio was 2.09, with a 95% confidence interval of 1.20 to 3.61. Neither age nor sex remained significantly associated with visual impairment after adjustment, suggesting that the territorial context is a more robust predictor of visual health outcomes in this population.

The study also examined visual acuity for each eye separately. Right eye visual acuity showed a statistically significant association with school location, but not with grade level, sex, or age. Left eye visual acuity was associated with school location, grade level, and age. However, the authors noted that since there is no clinical reason for these characteristics to affect one eye selectively, the differences between the eyes are more likely due to chance than to a real effect. The eye-specific analyses should therefore be interpreted with caution, as the main conclusions of the study rely on overall visual acuity defined by the worse eye.

The authors discussed several potential reasons for the higher prevalence of visual impairment in urban areas, including differences in access to eye care services, lifestyle factors, and near-work demands. In the Amazonas region, specialized eye care services are often unavailable in rural areas, forcing students to travel to larger cities for evaluation. Conversely, urban areas may have greater exposure to digital devices and prolonged near-work activities, which have been associated with myopia and other refractive errors in other studies. However, the study did not directly assess access, referral, or treatment, so these factors remain speculative.

Several limitations of the study were acknowledged by the authors. The cross-sectional design means that the findings show associations but not causal relationships. Visual acuity was measured with the Snellen chart, which is a valid screening tool but does not replace a comprehensive eye examination or identify the type of refractive error. Since no refractive evaluation was performed, the study documents the burden of reduced visual acuity but cannot determine how much of it is due to uncorrected refractive error or other eye conditions. The small sample size and uneven distribution between schools also reduced the power of the rural subgroup analyses.

The study underscores the need for comprehensive eye examinations to establish the causes of visual impairment and determine the most appropriate interventions. The findings point to an unmet eye-health need in this population, particularly in urban areas where the prevalence of impairment is higher. Strengthening school-based vision screening, ensuring timely referrals, and involving nurses and families in connecting students with specialized services are essential steps to address this issue. Future research should include refractive assessment and consider factors such as screen use, time spent outdoors, and prior access to eye care to gain a deeper understanding of the determinants of adolescent vision health in rural and urban settings.

In conclusion, the study provides valuable evidence on the disparities in visual acuity among adolescents in Peru’s Amazonas region. The higher prevalence of visual impairment in urban schools, which persists after adjusting for age and sex, highlights the importance of considering the territorial context when planning school eye-health actions. Integrating visual acuity assessment as a regular preventive practice in the school environment is crucial for early detection and intervention, ensuring that students receive the care they need to support their academic development and overall well-being.

Subject of Research: Comparison of visual acuity and impairment prevalence between rural and urban secondary school students in Peru's Amazonas region

Article Title: Visual impairment among adolescents attending rural and urban schools in Peru

Article References: Peña Huaman, A. L., Tejada-Muñoz, S., Cruz Caro, O., & Huyhua-Gutierrez, S. C. (2026). Visual impairment among adolescents attending rural and urban schools in Peru. Frontiers in Health Services, 6, Article 2002198. https://doi.org/10.3389/frhs.2026.2002198

Image Credits: AI Generated

DOI: 10.3389/frhs.2026.2002198

Keywords: visual impairment, adolescent health, rural-urban disparity, eye screening, Peru, school health, refractive error, public health, Visual, impairment, adolescents, attending