Editing Myopia (section)

==Treatment==
[[File:Briller2.JPG|right|thumb|Glasses are commonly used to address myopia.]]The National Institutes of Health says there is no known way of preventing myopia, and the use of glasses or contact lenses does not affect its progression, unless the glasses or contact lenses are too strong of a prescription.<ref>[https://www.nlm.nih.gov/medlineplus/ency/article/001023.htm Near-sightedness] {{webarchive|url=https://web.archive.org/web/20160510130838/https://www.nlm.nih.gov/medlineplus/ency/article/001023.htm|date=10 May 2016}}. National Institutes of Health. 2010.</ref> There is no universally accepted method of preventing myopia and proposed methods need additional study to determine their effectiveness.<ref name="AOA" /> Optical correction using [[glasses]] or [[contact lens]]es is the most common treatment; other approaches include [[orthokeratology]], and [[refractive surgery]].<ref name="AOA" />{{rp|21–26}} Medications (mostly [[atropine]]) and [[vision therapy]] can be effective in addressing the various forms of [[pseudomyopia]]. [[File:Myopia and lens correction.svg|thumb|Compensating for myopia using a corrective lens]]

===Glasses and contacts===
{{multiple image
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| image1 = Nearsighted color fringing -9.5 diopter - Canon PowerShot A640 thru glasses - overview.jpg
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| image2 = Nearsighted color fringing -9.5 diopter - Canon PowerShot A640 thru glasses - closeup detail.jpg
| width2 = 200
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| caption2 =
| footer = Prismatic color distortion shown with a camera set for near-sighted focus, and using −9.5 [[diopter]] eyeglasses to correct the camera's myopia (''left''). Close-up of color shifting through corner of eyeglasses. The light and dark borders visible between color swatches do not exist (''right'').
}}

[[Corrective lens]]es [[Refraction|bend]] the light entering the eye in a way that places a focused image accurately onto the retina. The power of any lens system can be expressed in [[diopter]]s, the [[Multiplicative inverse|reciprocal]] of its [[focal length]] in meters. Corrective lenses for myopia have negative powers because a divergent lens is required to move the [[far point]] of focus out to the distance. More severe myopia needs lens powers further from zero (more negative). However, strong eyeglass prescriptions create distortions such as prismatic movement and [[chromatic aberration]]. Strongly myopic wearers of [[contact lens]]es do not experience these distortions because the lens moves with the cornea, keeping the optic axis in line with the visual axis and because the vertex distance has been reduced to zero.

===Surgery===
[[Refractive surgery]] includes procedures which alter the corneal curvature of some structure of the eye or which add additional refractive means inside the eye.

====Photorefractive keratectomy====
{{see also|Photorefractive keratectomy}}
Photorefractive keratectomy (PRK) involves ablation of corneal tissue from the corneal surface using an [[excimer laser]]. The amount of tissue ablation corresponds to the amount of myopia. While PRK is a relatively safe procedure for up to 6 dioptres of myopia, the recovery phase post-surgery is usually painful.<ref>{{cite journal | vauthors = Trokel SL, Srinivasan R, Braren B | title = Excimer laser surgery of the cornea | journal = American Journal of Ophthalmology | volume = 96 | issue = 6 | pages = 710–5 | date = December 1983 | pmid = 6660257 | doi = 10.1016/s0002-9394(14)71911-7 }}</ref><ref>{{cite journal | vauthors = Seiler T, Bende T, Wollensak J, Trokel S | title = Excimer laser keratectomy for correction of astigmatism | journal = American Journal of Ophthalmology | volume = 105 | issue = 2 | pages = 117–24 | date = February 1988 | pmid = 3341427 | doi = 10.1016/0002-9394(88)90173-0 }}</ref>

====LASIK====
In a [[LASIK]] pre-procedure, a corneal flap is cut into the cornea and lifted to allow the excimer laser beam access to the exposed corneal tissue. After that, the excimer laser ablates the tissue according to the required correction. When the flap again covers the cornea, the change in curvature generated by the laser ablation proceeds to the corneal surface. Though LASIK is usually painless and involves a short rehabilitation period post-surgery, it can potentially result in flap complications and loss of corneal stability (post-LASIK [[keratectasia]]).<ref>{{cite journal | vauthors = Pallikaris IG, Siganos DS | title = Laser in situ keratomileusis to treat myopia: early experience | journal = Journal of Cataract and Refractive Surgery | volume = 23 | issue = 1 | pages = 39–49 | year = 1997 | pmid = 9100106 | doi = 10.1016/s0886-3350(97)80149-6 | s2cid = 38655546 }}</ref><ref>{{cite journal | vauthors = Pallikaris IG, Kymionis GD, Astyrakakis NI | title = Corneal ectasia induced by laser in situ keratomileusis | journal = Journal of Cataract and Refractive Surgery | volume = 27 | issue = 11 | pages = 1796–802 | date = November 2001 | pmid = 11709254 | doi = 10.1016/s0886-3350(01)01090-2 | s2cid = 2333450 }}</ref>

====Phakic intra-ocular lens====
Instead of modifying the corneal surface, as in laser vision correction (LVC), this procedure involves implanting an additional lens inside the eye (i.e., in addition to the already existing natural lens). While it usually results in good control of the refractive change, it can induce potential serious long-term complications such as glaucoma, cataract and endothelial decompensation.<ref>{{cite journal | vauthors = Menezo JL, Peris-Martínez C, Cisneros-Lanuza AL, Martínez-Costa R | title = Rate of cataract formation in 343 highly myopic eyes after implantation of three types of phakic intraocular lenses | journal = Journal of Refractive Surgery | volume = 20 | issue = 4 | pages = 317–24 | year = 2004 | pmid = 15307392 | doi = 10.3928/1081-597X-20040701-03 }}</ref><ref>{{cite journal | vauthors = Torun N, Bertelmann E, Klamann MK, Maier AK, Liekfeld A, Gonnermann J | title = Posterior chamber phakic intraocular lens to correct myopia: long-term follow-up | journal = Journal of Cataract and Refractive Surgery | volume = 39 | issue = 7 | pages = 1023–8 | date = July 2013 | pmid = 23664355 | doi = 10.1016/j.jcrs.2013.01.041 | s2cid = 31750663 }}</ref><ref>{{cite journal | vauthors = Moshirfar M, Imbornoni LM, Ostler EM, Muthappan V | title = Incidence rate and occurrence of visually significant cataract formation and corneal decompensation after implantation of Verisyse/Artisan phakic intraocular lens | journal = Clinical Ophthalmology | volume = 8 | pages = 711–6 | year = 2014 | pmid = 24748765 | pmc = 3986296 | doi = 10.2147/OPTH.S59878 | doi-access = free }}</ref>

===Orthokeratology===
{{main|Orthokeratology}}
Orthokeratology or simply Ortho-K is a temporary corneal reshaping process using rigid gas permeable (RGP) contact lenses.<ref>{{cite web |title=Orthokeratology (Ortho-k) – Corneal Reshaping with GP Contacts |url=https://www.contactlenses.org/orthok.htm |website=www.contactlenses.org}}</ref> Overnight wearing of specially designed contact lenses will temporarily reshape cornea, so patients may see clearly without any lenses in daytime. Orthokeratology can correct myopia up to −6D.<ref name="OW-OK">{{cite web |title=Orthokeratology: A Heated Debate Continues |url=https://www.ophthalmologyweb.com/Tech-Spotlights/26435-Orthokeratology-A-Heated-Debate-Continues/ |website=www.ophthalmologyweb.com |language=en}}</ref> Several studies shown that Ortho-K can reduce myopia progression also.<ref name="AAO-OK">{{cite web |title=Orthokeratology slows myopic progression in young patients |url=https://www.aao.org/editors-choice/orthokeratology-slows-myopic-progression-in-young- |website=American Academy of Ophthalmology |language=en |date=17 April 2019}}</ref><ref name="MPC-OK">{{cite web |title=Orthokeratology (Ortho-K) treatment for Myopia Prevention and Control |url=http://www.myopiaprevention.org/orthokeratology.html |website=www.myopiaprevention.org |access-date=4 June 2020 |archive-date=6 February 2020 |archive-url=https://web.archive.org/web/20200206215037/http://www.myopiaprevention.org/orthokeratology.html |url-status=dead }}</ref> Risk factors of using Ortho-K lenses include microbial keratitis,<ref name="AAO-OK" /> corneal edema,<ref name="RO-OK">{{cite web | vauthors = Daniels K |title=Consider Ortho-K For Myopia Control |url=https://www.reviewofoptometry.com/article/consider-ortho-k-for-myopia-control#:~:text=Safety%20Concerns%20and%20Side%20Effects&text=As%20with%20all%20contact%20lens,ocular%20abrasion%20or%20visual%20distortion. |website=www.reviewofoptometry.com}}</ref> etc. Other contact lens related complications such as corneal aberration, photophobia, pain, irritation, redness etc. are usually temporary conditions, which may be eliminated by proper usage of lenses.<ref name="RO-OK" />

===Intrastromal corneal ring segment===
The [[Intrastromal corneal ring segment]] (ICRS), commonly used in [[keratoconus]] treatment now, was originally designed to correct mild to moderate myopia.<ref>{{cite journal | vauthors = Vega-Estrada A, Alio JL | title = The use of intracorneal ring segments in keratoconus | journal = Eye and Vision | volume = 3 | pages = 8 | date = 15 March 2016 | pmid = 26981548 | pmc = 4791885 | doi = 10.1186/s40662-016-0040-z | doi-access = free }}</ref> The thickness is directly related to flattening and the diameter of the ring is proportionally inverse to the flattening of cornea. So, if diameter is smaller or thickness is greater, resulting myopia correction will be greater.<ref name="AAO-ICRS">{{cite web | vauthors = Pathak AK, Villarreal Gonzalez AJ, Karacal H |title=ICRS: Corneal biomechanics effects |url= https://eyewiki.aao.org/ICRS%3A_Corneal_biomechanics_effects#:~:text=Thus%2C%20the%20smaller%20the%20diameter,thickness)%20with%20higher%20myopic%20correction.&text=This%20flattening%20effect%20on%20the,separation%20and%20increased%20corneal%20flattening.}}</ref>

===Alternative medicine===
A number of [[alternative medicine|alternative therapies]] have been claimed to improve myopia, including [[vision therapy]], "behavioural optometry", various eye exercises and relaxation techniques, and the [[Bates method]].<ref name="Bates">Bates, Wm H (1920) [https://en.wikisource.org/wiki/Perfect_Sight_Without_Glasses/Chapter_10 Sight Without Glasses] {{webarchive|url=https://web.archive.org/web/20161220174710/https://en.wikisource.org/wiki/Perfect_Sight_Without_Glasses/Chapter_10 |date=20 December 2016 }}. Ch. 10, p. 106. {{ISBN|1479118540}}.</ref> Scientific reviews have concluded that there was "no clear scientific evidence" that eye exercises are effective in treating myopia<ref name="Rawstron">{{cite journal | vauthors = Rawstron JA, Burley CD, Elder MJ | title = A systematic review of the applicability and efficacy of eye exercises | journal = Journal of Pediatric Ophthalmology and Strabismus | volume = 42 | issue = 2 | pages = 82–8 | year = 2005 | doi = 10.3928/01913913-20050301-02 | pmid = 15825744 }}</ref> and as such they "cannot be advocated".<ref name="Barrett">{{cite journal | vauthors = Barrett BT | title = A critical evaluation of the evidence supporting the practice of behavioural vision therapy | journal = Ophthalmic & Physiological Optics | volume = 29 | issue = 1 | pages = 4–25 | date = January 2009 | pmid = 19154276 | doi = 10.1111/j.1475-1313.2008.00607.x | s2cid = 13588501 | doi-access = free }}</ref>