Editing Myopia (section)

===Age at onset===
Myopia is sometimes classified by the age at onset:<ref name="Grosvenor" />
* Congenital myopia, also known as infantile myopia, is present at birth and persists through infancy.<ref name="AOA" />
* Youth onset myopia occurs in early childhood or teenage, and the ocular power can keep varying until the age of 21, before which any form of corrective surgery is usually not recommended by ophthalmic specialists around the world.<ref name="AOA" />
* School myopia appears during childhood, particularly the school age years.<ref name="Morgan 1">{{cite journal | vauthors = Morgan I, Rose K | title = How genetic is school myopia? | journal = Progress in Retinal and Eye Research | volume = 24 | issue = 1 | pages = 1–38 | date = January 2005 | pmid = 15555525 | doi = 10.1016/j.preteyeres.2004.06.004 | s2cid = 18045281 }}</ref> This form of myopia is attributed to the use of the eyes for close work during the school years.<ref name="Cline" /> A 2004–2015 Singapore–Sydney study of children of Chinese descent found that time spent on outdoor activities was a factor.<ref>{{Cite web |url=http://www.smj.org.sg/article/school-based-programme-address-childhood-myopia-singapore |title=School based program |access-date=10 November 2022 |archive-date=10 November 2022 |archive-url=https://web.archive.org/web/20221110222346/http://www.smj.org.sg/article/school-based-programme-address-childhood-myopia-singapore |url-status=dead }}</ref>
* Adult onset myopia

:* Early adult onset myopia occurs between ages 20 and 40.<ref name="AOA" />
:*Late adult onset myopia occurs after age 40.<ref name="AOA" />