Refractive Errors and Amblyopia in Mexican Children Aged 6–12 Years: Clinical Prevalence and Visual Impact

Abstract

Highlights: What are the main findings? Myopia is the most clinically prevalent refractive error in Mexican children. Astigmatism is the main contributor to refractive amblyopia and related visual impairment in Mexican outpatient children. What are the implications of the main findings? It is important to implement and strengthen school-based screening programs for refractive errors and for amblyopia. Training initiatives for teachers and school health personnel, along with public awareness campaigns led by optometrists, are essential. Background: Refractive errors (REs) and amblyopia are the leading causes of visual impairment (VI) in children worldwide; however, national data for Mexico are scarce. Objective: We aim to estimate the clinical prevalence of RE, refractive amblyopia, and associated visual impairment (VI) in Mexican children aged 6–12 years. Methods: We analyzed 784,372 non-cycloplegic eye examinations from Salud Digna outpatient clinics across all 32 Mexican states (2021–2025). REs were classified as myopia (≤−0.50 D), hyperopia (≥+2.00 D), or astigmatism (≤ −1.00 D cylinder). Refractive amblyopia was defined as best-corrected visual acuity ≤ 20/30 in the most affected eye. The VI categories followed the WHO criteria. Results: Myopia was the most frequent (43.86%), followed by astigmatism (38.41%) and hyperopia (1.29%). Refractive amblyopia affected 4.94% of the children, predominantly due to astigmatic isoametropia (72.19%). VI related to refractive amblyopia occurred in 1.20% (mild), 0.37% (moderate), 0.01% (severe), and 0.01% (blindness) of children. Men showed a higher prevalence of RE and refractive amblyopia (p < 0.01). Geographic disparities were evident, with the central and southern states reporting the highest RA rates. Conclusions: Our outpatient-based study underscores REs, refractive amblyopia, and astigmatic ametropia as significant public health concerns in Mexican school-aged children. The high prevalence of uncorrected REs and refractive amblyopia highlights the need for nationwide school-based screening programs and early intervention strategies to mitigate long-term visual and developmental consequences.