Prevalence of Uncorrected Refractive Errors in Schoolchildren; A Crucial Vision Screening to Consider!

To determine the prevalence of the uncorrected refractive errors in Bojnourd students In a cross-sectional study, the samples were selected proportionate to the population of the schools using stratified randomized cluster sampling. The target population was the primary and junior high school students of the city of Bojnourd. Visual acuity (VA) (Snellen chart) and cycloplegic, non-cycloplegic and subjective refraction were measured in all students. Uncorrected visual acuity (UCVA) was defined as improvement in corrected vision for at least 2 lines as compared to the presenting vision. Of 2,020 selected students, 1,551 were included in the study (response rate 76.7%). The prevalence of uncorrected refractive errors was 6.2% (95% CI: 5-7.4) in at least one eye and 2.8% of the students had uncorrected refractive errors in both eyes. The prevalence of the uncorrected refractive errors was marginally higher in girls (p=0.068). Age, education level of the father and employment of the mother did not correlate with uncorrected refractive error. Myopic individuals followed by astigmatic students had the highest uncorrected refractive error. The presenting vision did not differ with the corrected vision in 83.3% of the participants. In 2.5% and 0.8% of the study population, vision improved by at least 3 and 4 lines after correcting vision, respectively. In individuals with glasses, the vision improved by at least 2, 3 and 4 lines in 21.1%, 9.5% and 3.2% respectively as compared to their present glasses. The prevalence of the uncorrected refractive errors in students was not low in this study. Girls, myopes, and cases of astigmatism showed high rates of uncorrected refractive errors, and it is important that they receive attention. Correcting these errors can help prevent visual impairment at young ages. Identifying uncorrected refractive errors should be among priorities of the health system, specially for students.