Prevalence of refractive errors, visual impairment, and nutritional status among primary schoolchildren in Mexico

Abstract The global prevalence of refractive errors and malnutrition among school-aged children is a significant concern, with limited data available from Mexico. A school-based study was conducted in three Mexican states, evaluating the refractive status, visual acuity, and nutritional status of 35,511 schoolchildren in 2025. Refractive errors were categorized as myopia (≤ -0.5D), astigmatism (≤ -0.75D cylinder), and hyperopia ( > + 2.0D). Visual acuity was classified as normal visual acuity (≥ 6/12), mild visual impairment (< 6/12 to ≥ 6/18), moderate visual impairment (< 6/18 to ≥ 6/60), severe visual impairment (< 6/60 to ≥ 3/60), and blindness (< 3/60). The BMI categories based on z-scores included low weight (<-2 SD), normal weight (≥-2 to ≤ + 1 SD), overweight (> 1 to < 2 SD), and obesity ( ≥ + 2 SD). Myopia-astigmatism was the most prevalent refractive error (28.88%) followed by astigmatism (17.13%). Less than 2% of children had a visual impairment, primarily due to myopia-astigmatism, and no cases of blindness were reported. Less than 1.55% of children had low weight, with a decrease in normal weight as they aged and a corresponding increase in overweight and obesity. In overweight children, myopia-astigmatism surpassed emmetropia after 11-years old, whereas in obese children, this shift occurred at 8-year-old. Programs targeting schoolchildren must be developed and implemented to improve their visual and nutritional health, thereby preventing long-term complications. Further research is needed to establish a relationship between nutritional status and the prevalence of refractive errors.