Editing Floater (section)

== Causes ==
There are various causes for the appearance of floaters, of which the most common are described here.

Floaters can occur when eyes age; in rare cases, floaters may be a sign of [[retinal detachment]] or a [[retinal tear]].<ref name="NHSChoices">{{cite web |url=http://www.nhs.uk/conditions/floaters/pages/introduction.aspx |title=Floaters |author=<!--Not stated--> |website=NHS choices |publisher=NHS GOV.UK |access-date=September 17, 2017 |archive-date=September 17, 2017 |archive-url=https://web.archive.org/web/20170917171548/http://www.nhs.uk/conditions/floaters/pages/introduction.aspx |url-status=dead }}</ref><ref name="Alila Medical Media-2020" />

=== Vitreous syneresis ===
Vitreous syneresis (liquefaction) and contraction with age can cause vitreous floaters. Additionally, trauma or injury to the globe can cause them.<ref name=stat>{{cite journal |author1=Reece Bergstrom |author2=Craig N. Czyz. |title=Vitreous Floaters|date=2020 |journal=Statpearls |pmid=29262091}}{{CC-notice|cc=by4|url=https://www.ncbi.nlm.nih.gov/books/NBK470420/}}</ref><ref name="Alila Medical Media-2020" />

=== Vitreous detachments ===
[[File:Vitreous Floaters.jpg|right|thumb|Weiss ring: a large, ring shaped floater that is sometimes seen if the vitreous body releases from the back of the eye]]
As part of the normal human aging process the liquefied vitreous body loses support and contracts. This leads to [[posterior vitreous detachment]] in which the [[vitreous membrane]] is released from the sensory retina.<ref name="Alila Medical Media-2020" /> During this detachment, the shrinking vitreous can [[phosphene|stimulate the retina mechanically]],<ref name="Alila Medical Media-2020" /> causing the patient to see random flashes across the visual field, sometimes referred to as "flashers", a symptom more formally referred to as [[photopsia]]. The ultimate release of the vitreous around the optic nerve head sometimes makes a large floater appear, usually in the shape of a ring ("Weiss ring").<ref>{{cite web |title=Flashes & Floaters |url=http://www.agingeye.net/visionbasics/flashesandfloaters.php |archive-url=https://web.archive.org/web/20080725211059/http://www.agingeye.net/visionbasics/flashesandfloaters.php |archive-date=25 July 2008 |access-date=2008-02-24 |publisher=The Eye Digest}}</ref>

Posterior vitreous detachment is more common in people who:
* are [[Near-sightedness|nearsighted]];
* have undergone [[cataract surgery]] or [[clear lens extraction]];
* have had [[Nd:YAG laser]] surgery of the eye;
* have had inflammation inside the eye.<ref>American Academy of Ophthalmology – patient education pamphlet</ref>{{Better source needed|reason=Source isn't cited properly, and isn't sufficient enough.|date=March 2022}}

=== Retinal detachment ===
As a complication of Vitreous detachment, part of the retina might be torn off by the departing vitreous membrane causing a [[retinal detachment]]. A retinal tear may also allow fluid to leak behind the retina, causing it to detach. This will often leak blood into the vitreous, which is seen by the patient as a sudden appearance of numerous small black dots or ribbons moving across the field of vision. Sometimes a gray curtain may appear to partially block vision in one eye. Retinal detachment requires immediate medical attention,<ref name="Alila Medical Media-2020" /> as it can easily cause [[blindness]]. Consequently, both the appearance of flashes and the sudden onset of numerous small floaters should be rapidly investigated by an eye care provider, preferably a retinal ophthalmologist.<ref name=det>{{cite web| title =Flashes and Floaters (Posterior Vitreous Detachment)| publisher= St. Luke's Cataract & Laser Institute| url =http://www.stlukeseye.com/Conditions/floaters.html| access-date =2008-02-01| url-status =dead| archive-url =https://web.archive.org/web/20100502083133/http://www.stlukeseye.com/Conditions/Floaters.html| archive-date =2010-05-02}}</ref>

=== Regression of the hyaloid artery ===
The [[hyaloid artery]], an artery running through the vitreous humour during the [[fetus|fetal]] stage of development, regresses in the third trimester of [[pregnancy]]. Its disintegration can sometimes leave cell matter.<ref>{{Cite journal |last=Petersen |first=Hans Peter |date=1968 |title=PERSISTENCE OF THE BERGMEISTER PAPILLA WITH GLIAL OVERGROWTH: Various Diagnostic Problems |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1755-3768.1968.tb02826.x |journal=Acta Ophthalmologica |language=en |volume=46 |issue=3 |pages=430–440 |doi=10.1111/j.1755-3768.1968.tb02826.x |pmid=5755733 |issn=1755-375X}}</ref>

=== Other common causes ===
Patients with [[retinal tear]]s may experience floaters if [[red blood cell]]s are released from leaky blood vessels, and those with [[uveitis]] or vitritis, as in [[toxoplasmosis]], may experience multiple floaters and decreased vision due to the accumulation of [[white blood cell]]s in the vitreous humour.<ref>{{cite web|url=http://www.optometry.co.uk/uploads/articles/640c1a5b606a7d89320511ca29ccc288_kabat20010323.pdf|title=A clinician's guide to flashes and floaters|author=Alan G. Kabat|author2=Joseph W. Sowka|publisher=optometry.co.uk|date=April 2009|access-date=2008-04-10|url-status=dead|archive-url=https://web.archive.org/web/20120708191532/http://www.optometry.co.uk/uploads/articles/640c1a5b606a7d89320511ca29ccc288_kabat20010323.pdf|archive-date=2012-07-08}}</ref>

Other causes for floaters include [[cystoid macular edema]] and [[asteroid hyalosis]]. The latter is an anomaly of the vitreous humour, whereby [[calcium]] clumps attach themselves to the collagen network. The bodies that are formed in this way move slightly with eye movement, but then return to their fixed position.{{citation needed|date=August 2017}}