Refractive Error and Visual Function in Children Under Non-cycloplegic Screening Conditions

Background: To assess the prevalence of refractive error and reduced uncorrected visual acuity (UCVA) in children, and to evaluate the extent to which visual acuity reflects refractive status under conditions similar to those used in primary care and school-based vision screening.Methods: A cross-sectional study was conducted in 190 children (mean age 8.35 ± 2.94 years) attending routine optometric examinations in Lisbon, Portugal. Refractive status was assessed by non-cycloplegic retinoscopy and classified using spherical equivalent. UCVA was measured with logMAR charts. Reduced UCVA was defined as >0.10 logMAR. Multivariable logistic regression was performed to identify factors associated with reduced UCVA.Results:

Hyperopia was the most common refractive status (56.8%), followed by emmetropia (22.6%) and myopia (20.5%), with a shift toward myopia with increasing age. Reduced UCVA was present in 30.5% of children and increased with age. Among children with reduced UCVA, 67.2% were not using optical correction. However, because UCVA was measured under deliberately uncorrected conditions, this finding should not be interpreted as confirmed presenting visual impairment or definitive unmet need, but rather as an indicator of potential need for further visual assessment. Notably, 68.7% of children with refractive error had normal UCVA, while 6.3% without refractive error showed reduced UCVA.Conclusions: In this pediatric clinical sample, visual acuity alone may not reliably reflect refractive status, particularly for low-magnitude refractive errors, under non-cycloplegic, routine screening-like conditions. However, because the study included children attending routine optometric examinations rather than a school-based or population-based sample, the findings should not be interpreted as population-representative and should be generalized with caution.

Keywords: refractive error, uncorrected visual acuity, pediatric population, vision screening, visual function