Editing Myopia (section)

===Environmental factors===
Environmental factors that increase the risk of myopia include insufficient light exposure, low physical activity, near work, and increased years of education.<ref name=Val2019/><ref name=":7" />

One hypothesis is that a lack of normal visual stimuli causes improper development of the eyeball. Under this hypothesis, "normal" refers to the environmental stimuli that the eyeball evolved to.<ref name="Lieberman">Lieberman, Daniel E. (2013) ''The Story of the Human Body: Evolution, Health, and Disease''. New York: Pantheon Books.{{page needed|date=January 2022}}</ref> Modern humans who spend most of their time indoors, in dimly or fluorescently lit buildings may be at risk of development of myopia.<ref name="Lieberman"/>

People, and children especially, who spend more time doing [[physical exercise]] and [[Outdoor recreation|outdoor play]], have lower rates of myopia,<ref name="BBC">{{cite news|url=https://www.bbc.co.uk/news/health-15427954|title=Lack of outdoor play linked to short-sighted children| vauthors = Sherwin J |date=25 October 2011|work=BBC News|access-date=25 October 2011|archive-url=https://web.archive.org/web/20111025171847/http://www.bbc.co.uk/news/health-15427954|archive-date=25 October 2011|url-status=live}}</ref><ref name="Lieberman"/><ref name="Dirani">{{cite journal | vauthors = Dirani M, Tong L, Gazzard G, Zhang X, Chia A, Young TL, Rose KA, Mitchell P, Saw SM | display-authors = 6 | title = Outdoor activity and myopia in Singapore teenage children | journal = The British Journal of Ophthalmology | volume = 93 | issue = 8 | pages = 997–1000 | date = August 2009 | pmid = 19211608 | doi = 10.1136/bjo.2008.150979 | s2cid = 30301026 }}</ref><ref name="Rose">{{cite journal | vauthors = Rose KA, Morgan IG, Ip J, Kifley A, Huynh S, Smith W, Mitchell P | title = Outdoor activity reduces the prevalence of myopia in children | journal = Ophthalmology | volume = 115 | issue = 8 | pages = 1279–85 | date = August 2008 | pmid = 18294691 | doi = 10.1016/j.ophtha.2007.12.019 }}</ref><ref name="Dolgin" /> suggesting the increased magnitude and complexity of the visual stimuli encountered during these types of activities decrease myopic progression. There is preliminary evidence that the protective effect of outdoor activities on the development of myopia is due, at least in part, to the effect of long hours of exposure to [[daylight]] on the production and the release of retinal [[dopamine]].<ref name="Dolgin"/><ref>{{cite journal | vauthors = Cui D, Trier K, Munk Ribel-Madsen S | title = Effect of day length on eye growth, myopia progression, and change of corneal power in myopic children | journal = Ophthalmology | volume = 120 | issue = 5 | pages = 1074–9 | date = May 2013 | pmid = 23380471 | doi = 10.1016/j.ophtha.2012.10.022 }}</ref><ref name="pmid23434455">{{cite journal | vauthors = Feldkaemper M, Schaeffel F | title = An updated view on the role of dopamine in myopia | journal = Experimental Eye Research | volume = 114 | pages = 106–19 | date = September 2013 | pmid = 23434455 | doi = 10.1016/j.exer.2013.02.007 | s2cid = 35493712 | type = review }}</ref><ref name="pmid23298452">{{cite journal | vauthors = Nickla DL | title = Ocular diurnal rhythms and eye growth regulation: where we are 50 years after Lauber | journal = Experimental Eye Research | volume = 114 | pages = 25–34 | date = September 2013 | pmid = 23298452 | pmc = 3742730 | doi = 10.1016/j.exer.2012.12.013 | type = Review }}</ref>

Myopia can be induced with minus spherical lenses,<ref>{{cite journal |last1=Nickla |first1=Debora L. |last2=Jordan |first2=Kelsey |last3=Yang |first3=Jane |last4=Totonelly |first4=Kristen |title=Brief hyperopic defocus or form deprivation have varying effects on eye growth and ocular rhythms depending on the time-of-day of exposure |journal=Experimental Eye Research |date=1 August 2017 |volume=161 |pages=132–142 |doi=10.1016/j.exer.2017.06.003 |pmid=28596085 |pmc=5557081 }}</ref> and overminus in prescription lenses can induce myopia progression.<ref>{{Cite web|url=https://www.reviewofoptometry.com/article/overminus-lenses-associated-with-myopia-progression|title = Overminus Lenses Associated with Myopia Progression}}</ref><ref name="overminus">https://www.optometrystudents.com/pearl/over-minus-you-probably-do-itstop-it/ {{Webarchive|url=https://web.archive.org/web/20221202062113/https://www.optometrystudents.com/pearl/over-minus-you-probably-do-itstop-it/ |date=2 December 2022 }}{{medrs|date=January 2022}}{{full citation needed|date=January 2022}}</ref> Overminus during refraction can be avoided through various techniques and tests, such as fogging, plus to blur, and the [[duochrome test]].<ref name="overminus" />

The near work hypothesis, also referred to as the "use-abuse theory", states that spending time involved in near work strains the intraocular and extraocular muscles. Some studies support the hypothesis, while other studies do not.<ref name=Pan2012/> While an association is present, it is not clearly causal.<ref name=Pan2012/>

Myopia is also more common in children with [[diabetes]], [[childhood arthritis]], [[uveitis]], and [[systemic lupus erythematosus]].<ref name=Val2019/>