Prevalence and Burden of Refractive Errors at National and Sub-national Levels in Iran


Purpose: To estimate the prevalence, burden of refractive errors and their associated trend from 1990 to 2018 and geographic inequalities in Iran.

Methods: Data regarding the epidemiology of refractive errors was extracted from three different sources: systematic review of published literature, data from visual school screening programs, and data from Iran’s national health survey (NHS). The pool of all available data on refractive errors as well as demographic, location, and socioeconomic status covariates were fitted in spatio-temporal and Gaussian process regression models to predict the prevalence of refractive errors from the years 1990 to 2018 in 31 provinces grouped by age and sex in order to calculate years lived with disability (YLDs).

Results: In 2018, the age-adjusted prevalence of refractive errors was 16.32% (95% uncertainty interval [UI]: 12.44–21.48%) in both sexes, 17.98% (95% UI: 13.74– 23.61%) in women, and 14.66% (95% UI: 11.14–19.36%) in men. The prevalence of refractive errors reveals that it increases with age. Refractive errors contributed to 441.41 and 348.38 YLDs in men and women, respectively. The age-standardized prevalence growth was 31.30% in females and 24.32% in males from the years 1990 to 2018. Significant geographical heterogeneity was observed. The age-standardized YLDs rates of refractive errors represent an increasing trend of 28.9% increase from 1990 to 2018.

Conclusion: Over 28 years, the prevalence of refractive errors increased significantly. Women tend to have higher rates of prevalence. The prevalence increased in older ages. Border provinces had the lowest prevalence. Age-standardized YLDs rates of refractive errors increased by about 30%.


Burden, Disability-adjusted Life Years, Iran, Prevalence, Refractive Errors

1. Naidoo KS, Leasher J, Bourne RR, Flaxman SR, Jonas JB, Keeffe J, et al. Global vision impairment and blindness due to uncorrected refractive error, 1990–2010. Optom Vis Sci 2016;93:227–234.

2. Kandel H, Khadka J, Goggin M, Pesudovs K. Impact refractive error on quality of life: a qualitative study. Clin Exp Ophthalmol 2017;45:677–688.

3. WHO. The global burden of disease: 2004 update [Internet]. Geneva: World Health Organization; 2008 [cited 2015 September 1]. Available from: June 25, 2019.

4. Holden BA. Blindness and poverty: a tragic combination. Clin Exp Optom 2007;90:401–403.

5. Tahhan N, Papas E, Fricke TR, Frick KD, Holden BA. Utility and uncorrected refractive error. Ophthalmology 2013;120:1736–1744.

6. Lou L, Yao C, Jin Y, Perez V, Ye J. Global patterns in health burden of uncorrected refractive error. Invest Ophthalmol Vis Sci 2016;57:6271–6277.

7. Murray CJ, Barber RM, Foreman KJ, Ozgoren AA, Abd- Allah F, Abera SF, et al. Global, regional, and national disability-adjusted life years (DALYs) for 306 diseases and injuries and healthy life expectancy (HALE) for 188 countries, 1990-2013: quantifying the epidemiological transition. Lancet 2015;386:2145–2191.

8. Pascolini D, Mariotti SP. Global estimates of visual impairment: 2010. Br J Ophthalmol 2012;96:614–618.

9. Hatef E, Mohammadi SF, Alinia C, Ashrafi E, Mohammadi SM, Lashay A, et al. National burden of eye diseases in Iran, 1990-2010; findings from the global burden of diseases study 2010. Middle East Afr J Ophthalmol 2016;23:89–95.

10. Ashrafi E, Mohammadi SF, Fotouhi A, Lashay A, Asadi-lari M, Mahdavi A, et al. National and sub-national burden of visual impairment in Iran 1990-2013; study protocol. Arch Iran Med 2014;17:810–815.

11. Hashemi H, Fotouhi A, Yekta A, Pakzad R, Ostadimoghaddam H, Khabazkhoob M. Global and regional estimates of prevalence of refractive errors: systematic review and meta-analysis. J Curr Ophthalmol 2017;30:3−22.

12. Dolgin E. The myopia boom. Nature 2015;519:276–278.

13. Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, et al. Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology 2016;123:1036–1042.

14. Ono K, Hiratsuka Y, Murakami A. Global inequality in eye health: country-level analysis from the global burden of disease study. Am J Public Health 2010;100:1784–1788.

15. Rahi JS, Cumberland PM, Peckham CS. Myopia over the life course: prevalence and early life influences in the 1958 British birth cohort. Ophthalmology 2011;118:797–804.

16. Huang HW, Teh Chang DS, Chang Wu P. The association between near work activities and myopia in children— a systematic review and meta-analysis. PLoS One 2015;10:e0140419.

17. French AN, Morgan IG, Mitchell P, Rose KA. Risk factors for incident myopia in Australian schoolchildren: the Sydney Adolescent Vascular and Eye Study. Ophthalmology 2013;120:2100–2108.

18. Zhang X, Cheung SSL, Chan HN, Zhang Y, Wang YM, Yip BH, et al. Myopia incidence and lifestyle changes among school children during the COVID-19 pandemic: a population-based prospective study. Br J Ophthalmol 2021;bjophthalmol-2021-319307.

19. The impact of myopia and high myopia. Report of the Joint World Health Organization–Brien Holden Vision Institute Global Scientific Meeting on Myopia. University of New South Wales, Sydney, Australia, March 16–18, 2015. Geneva: World Health Organization; 2017 [cited 2019 June 25]. Available from: causes/MyopiaReportforWeb.pdf.

20. Foster PJ, Jiang Y. Epidemiology of myopia. Eye 2014;28:202–208. 21. Wu PC, Tsai CL, Hu CH, Yang YH. Effects of outdoor activities on myopia among rural school children in Taiwan. Ophthalmic Epidemiol 2010;17:338–342.

22. Deng L, Gwiazda J, Thorn F. Children’s refractions and visual activities in the school year and summer. Optom Vis Sci 2010;87:406–413.

23. Dirani M, Tong L, Gazzard G. Outdoor activity and myopia in Singapore teenage children. Br J Ophthalmol 2009;93:997–1000.

24. Rose KA, Morgan IG Ip J. Outdoor activity reduces the prevalence of myopia in children. Ophthalmology 2008;115:1279–1285.

25. Jones LAS, Sinnott LT, Mutti DO, Mitchell GL, Moeschberger ML, Zadnik K. Parental history of myopia, sports and outdoor activities, and future myopia. Invest Ophthalmol Vis Sci 2007;48:3524–3532.

26. Onal S, Toker E, Akingol Z. Refractive errors of medical students in Turkey: one year follow-up of refraction and biometry. Optom Vis Sci 2007;84:175–180.