Myopia is becoming worse over the span of one generation so that now over 40% of the population in the United Sates is myopic. In Taiwan, 84% of 16-18 year olds were myopic in the year 2000 versus 74% 17 years earlier. The changes are rapid and they continue to worsen. But it is not universal - just as the incidence of myopia is extremely high in Taiwan, it is also extremely low in some areas. On the South Pacific Island of Vanuatu, 1.3% of the schoolchildren are myopic.
Understanding why a person's location can have such a strong effect on myopia is one of the challenges facing myopia researchers.Katie M. Williams, MPhil, Geir Bertelsen, Phillippa Cumberland, et al. (2015) Increasing Prevalence of Myopia in Europe and the Impact of Education. (FULL TEXT) Ophthalmology In Press doi: http://dx.doi.org/10.1016/j.ophtha.2015.03.018
MyopiaPrevention.org comment: Myopia increased 17.8% for those born between 1940-1979 compared to those born between 1910-1939. Those with higher education levels increased more although this factor did not account for all of the effect.Neil Charman.(2010) Myopia: its prevalence, origins and control. Ophthalmic and Physiological Optics Volume 31, Issue 1, pages 3–6, January 2011 (FULL TEXT) doi: 10.1111/j.1475-1313.2010.00808.x
MyopiaPrevention.org comment: This article is a brief yet concise overview of the history of myopia research and an introduction to a group of articles previously published in the journal and gathered here as a virtual issue: Ophthalmic and Physiological Optics Virtual Issue, July 2010 (Index)Yekta A, Fotouhi A, Hashemi H, Dehghani C, Ostadimoghaddam H, Heravian J, Derakhshan A, Yekta R, Behnia M, Khabazkhoob M.(2010) Prevalence of refractive errors among schoolchildren in Shiraz, Iran. (ABSTRACT) Clin Experiment Ophthalmol. 2010 Apr;38(3):242-8.
MyopiaPrevention.org comment: The prevalence of myopia in Iranian schoolchildren was 4.35%. This low number of myopes in literate, educated children contrasts sharply with rates over 50% in many industrialized areas of the world and is a further indication that reading does not cause myopia.Vitale S, Sperduto RD, Ferris FL 3rd. (2009) Increased prevalence of myopia in the United States between 1971-1972 and 1999-2004. (FULL TEXT) Arch Ophthalmol. 2009 Dec;127(12):1632-9
MyopiaPrevention.org comment: This is the study published at the end of 2009 that continues to draw national media attention showing that myopia increased 66 percent in the United States between 1971-1972 and 1999-2004. Rates for people aged 12-54 went from 25.0% of people in the former period to 41.6% of people myopic during the later time period, a span of roughly 30 years. Some have called this an "epidemic".Morgan IG, Rose KA, Ellwein LB; The Refractive Error Study in Children Survey Group(2009) Is emmetropia the natural endpoint for human refractive development? An analysis of population-based data from the refractive error study in children (RESC). (ABSTRACT) Acta Ophthalmol. 2009 Nov 24. [Epub ahead of print]
MyopiaPrevention.org comment: In a study of 38,811 children at five sites around the world, it was determined that mild hyperopia between +.75 and +2.00 is the normal state for children. If the child is emmetropic (between -.50 and +.50), they are considered at risk for progressing to myopia.Donald O. Mutti, John R. Hayes, G. Lynn Mitchell, Lisa A. Jones, Melvin L. Moeschberger, Susan A. Cotter, Robert N. Kleinstein, Ruth E. Manny, J. Daniel Twelker, Karla Zadnik for the CLEERE Study Group.(2007) Refractive Error, Axial Length, and Relative Peripheral Refractive Error before and after the Onset of Myopia. ( FULL TEXT) Investigative Ophthalmology and Visual Science. 2007;48:2510-2519.
MyopiaPrevention.org comment: A study of 975 children over ten years. The findings are relevant to certain factors having predictive value as to whether a student will become myopic and when it might occur. In summary, factors such as longer eyes, refractive errors moving towards myopia, increased peripheral hyperopia, and an increased rate of change of all these factors occur 2 to 4 years before the onset of myopia. It is a "narrow window of time" in which to detect potential problems.Hyman L, Gwiazda J, Hussein M, Norton TT, et al. (2005). Relationship of age, sex, and ethnicity with myopia progression and axial elongation in the correction of myopia evaluation trial. (COMET) (FULL TEXT) Arch Ophthalmol. 123: 977-87
MyopiaPrevention.org comment: Those students who developed myopia at an earlier age were the students who progressed the fastest and had the greatest axial elongation at 3 years. African-American students had the least change of the ethnic groups studied.Seang-Mei Saw, Gus Gazzard, Edwin Chan Shih-Yen, Wei-Han Chua. (2005) Myopia and associated pathological complications. (FULL TEXT) Ophthalmic Physiol Opt. 25(5): 381-91 DOI: 10.1111/j.1475-1313.2005.00298.x
MyopiaPrevention.org comment: Myopic patients have a greater incidence of cataract with myopia of greater than 6.00 diopters having a greater risk of glaucoma, retinal detachments, chorioretinal atrophy and lacquer cracks. Various studies for different pathologies are reviewed. "There is a public health need to prevent the onset or progression of myopia."Mutti DO, Zadnik K, Hayes JR, Mitchell GL, Jones LA, Moeschberger ML. (2004) The Effect of Ethnicity on Axial Length and Ocular Shape Before and After the Onset of Myopia .(ABSTRACT) Invest Ophthalmol Vis Sci 2005;46: E-Abstract 4623.
MyopiaPrevention.org comment: Asian–American children tended to show the most myopia, the fastest growth and the most prolate shape among African–American, Asian–American, Caucasian and Hispanic ethnicities.Kempen JH, Mitchell P, Lee KE, Tielsch JM, Broman AT, Taylor HR, Ikram MK, Congdon NG, O'Colmain BJ; Eye Diseases Prevalence Research Group. (2004) The prevalence of refractive errors among adults in the United States, Western Europe, and Australia. (FULL TEXT) Arch Ophthalmol. 2004 Apr;122(4):495-505
MyopiaPrevention.org comment: For those over 40 in the year 2000, a study of the prevalence of refractive error. Rates for myopia (-1.00 or worse) were 25.4% (US), 26.6% (Western Europe) and 16.4% (Australia). For those with more severe myopia (-5.00 or worse), the numbers were 4.5%, 4.6% and 2.8%.Lin LL, Shih YF, Hsiao CK, Chen CJ (2004). Prevalence of myopia in Taiwanese schoolchildren: 1983 to 2000. (ABSTRACT) Ann Acad Med Singapore 33: 27-33.
MyopiaPrevention.org comment: The severity of myopia was correlated with the increasingly younger age of onset over the years. The recommendation is to pay more attention to the vision of pre-school children.Villarreal MG, Ohlsson J, Abrahamsson M, Sjostrom A, Sjostrand J (2000). Myopisation: the refractive tendency in teenagers. Prevalence of myopia among young teenagers in Sweden. Acta Ophthalmol Scand. 2000 Apr;78(2):177-81. (ABSTRACT)
MyopiaPrevention.org comment: A review of myopia incidence in Sweden for 12-13 year olds. Fifty percent had at least low myopia, with 23% an amount equal to or greater than .75 and thus suggested as needing glasses. The results were considered similar to reports from other parts of the world.