Editing Refractive error (section)

==Epidemiology==
[[File:Refractive errors world map - DALY - WHO2004.svg|thumb|upright=1.3|[[Disability-adjusted life year|DALYs]] per 100,000 people due to refractive errors in 2004.<ref>{{cite web |url=https://www.who.int/healthinfo/global_burden_disease/estimates_country/en/index.html |title=WHO Disease and injury country estimates |year=2009 |work=World Health Organization |access-date=Nov 11, 2009 |url-status=live |archive-url=https://web.archive.org/web/20091111101009/http://www.who.int/healthinfo/global_burden_disease/estimates_country/en/index.html |archive-date=2009-11-11 }}</ref>{{Div col|small=yes|colwidth=10em}}
{{legend|#b3b3b3|No data}}
{{legend|#ffff65|Less than 100}}
{{legend|#fff200|100–170}}
{{legend|#ffdc00|170–240}}
{{legend|#ffc600|240–310}}
{{legend|#ffb000|310–380}}
{{legend|#ff9a00|380–450}}
{{legend|#ff8400|450–520}}
{{legend|#ff6e00|520–590}}
{{legend|#ff5800|590–660}}
{{legend|#ff4200|660–730}}
{{legend|#ff2c00|730–800}}
{{legend|#cb0000|More than 800}}
{{div col end}}]]
It is estimated that at least 2 billion people in the world have refractive errors.<ref name="OUP2014" /> The number of people globally with refractive errors that have not been corrected was estimated at 660 million (10 per 100 people) in 2013.<ref name=GBD2015/>

Refractive errors are the first common cause of visual impairment and second most common cause of visual loss .<ref>{{Cite journal|last1=Hashemi|first1=Hassan|last2=Fotouhi|first2=Akbar|last3=Yekta|first3=Abbasali|last4=Pakzad|first4=Reza|last5=Ostadimoghaddam|first5=Hadi|last6=Khabazkhoob|first6=Mehdi|date=2017-09-27|title=Global and regional estimates of prevalence of refractive errors: Systematic review and meta-analysis|journal=Journal of Current Ophthalmology|volume=30|issue=1|pages=3–22|doi=10.1016/j.joco.2017.08.009|issn=2452-2325|pmc=5859285|pmid=29564404}}</ref> The assessment of refractive error is now done in DALY (Disability Adjusted Life Years) which showed an 8% increase from 1990 to 2019.<ref>{{Cite web|title=Global Disease Burden of Uncorrected Refractive Error Among Adolescents From 1990 to 2019|url=https://assets.researchsquare.com/files/rs-459379/v1/67274026-a654-4b9a-aa55-cb38e2d5c6b3.pdf|access-date=2023-03-21|url-status=dead|archive-url=https://web.archive.org/web/20210624205636/https://assets.researchsquare.com/files/rs-459379/v1/67274026-a654-4b9a-aa55-cb38e2d5c6b3.pdf|archive-date=2021-06-24}}</ref>{{Unreliable source?|reason=Source states it shouldn't be used as a reference for validated info.|sure=y|date=March 2023}}

The number of people globally with significant refractive errors has been estimated at one to two billion.<ref name=OUP2014/> Rates vary between regions of the world with about 25% of Europeans and 80% of Asians affected.<ref name=OUP2014 /> Near-sightedness is one of the most prevalent disorders of the eye.<ref name=Fos2014/> Rates among adults are between 15 and 49% while rates among children are between 1.2 and 42%.<ref name=Pan2012/> Far-sightedness more commonly affects young children, whose eyes have yet to grow to their full length, and the elderly, who have lost the ability to compensate with their [[Accommodation (eye)|accommodation system]].<ref name=Cas2014/><ref name=Gro2007/> Presbyopia affects most people over the age of 35, and nearly 100% of people by the ages of 55–65.<ref name=NIH2010/> Uncorrected refractive error is responsible for visual impairment and disability for many people worldwide.<ref name=GBD2015/> It is one of the most common causes of [[vision loss]] along with [[cataract]]s, [[macular degeneration]], and [[vitamin A deficiency]].<ref name=Pan2015/>