Related Experiment Video
Updated: May 7, 2026
Subjective Refraction Test Using a Smartphone for Vision Screening
Published on: October 18, 2024
Incidence and Risk Factors of Refractive Error in Children in Spain: CISViT Project
Alba Galdón1,2, Laura Guisasola3,4, Mariam El Gharbi3,4
1Visió Optometria i Salut research group, Department of Optics and Optometry, Universitat Politècnica de Catalunya Terrassa, Barcelona, Spain. alba.galdon@upc.edu.
Background:
The incidence of refractive errors (RE), particularly myopia, has increased in recent years, presenting significant geographic variations. This prospective longitudinal cohort study aims to assess the incidence of RE in a school-based cohort in northeastern Spain and identify associated risk factors.
Methods:
The study followed up 1189 children with an ~1-year interval (mean age: 8.74 years at visit 1 and 10.00 years at visit 2) from a school-based cohort in northeast Spain (2021-2024). RE was measured using an autorefractometer and retinoscopy without cycloplegia. A preliminary questionnaire was used to collect data on potential risk factors such as visual habits and socioeconomic status.
Results:
The spherical equivalent (SE) at the initial visit was +0.29 ± 0.03 D, decreasing to +0.14 ± 0.04 D at follow-up. The prevalence of myopia increased from 12.3% at baseline to 17.1% at follow-up. A total of 56 incident cases were identified, corresponding to a cumulative incidence of 5.4%. In multivariable logistic regression, baseline SE ≤ +1.00 D was associated with a clinically significant myopic shift (odds ratio (OR) = 1.67, 95% CI 1.29-2.16; p < 0.001). Parental myopia was strongly associated with the outcome (maternal: OR = 23.36, 95% CI 8.33-65.49; p < 0.001; paternal: OR = 4.25, 95% CI 1.74-10.38; p < 0.001). Lower outdoor exposure was also associated with higher odds of a clinically significant myopic shift (low vs. high: OR = 9.33, 95% CI 5.89-14.79; p < 0.001). Parental education was not significantly associated, whereas parental unemployment was associated with higher odds of myopic shift in the fully adjusted model.
Conclusions:
The incidence of myopia and progression of RE (change in SE) in this school-based cohort of northeastern Spanish schoolchildren was significant over 1 year. Factors such as paternal/maternal myopia, reduced outdoor time and both paternal and maternal unemployment were associated with a higher risk of a clinically significant myopic shift (ΔSE ≤ -0.50 D).
