This article or section is missing citations and/or footnotes. Using inline citations helps guard against copyright violations and factual inaccuracies. You may improve the article or discuss this issue on its talk page. Help on using footnotes is available. This article has been tagged since April 2007. Image File history File links Information. ...

Impression of severe case of floaters, as seen against a blue sky.

Floaters are deposits of various size, shape, consistency, refractive index, and motility within the eye's normally transparent vitreous humour.^[1] They may be of embryonic origin or acquired due to degenerative changes of the vitreous humour or retina.^[1] The perception of floaters is known as myodesopsia, or less commonly as myiodeopsia, myiodesopsia, or myodeopsia.^[1] When observed subjectively, floaters are entoptic phenomena characterized by shadow-like shapes that appear singly or together with several others in one's field of vision. They may appear as spots, threads, or fragments of cobwebs, which float slowly before one's eyes. Look up floater in Wiktionary, the free dictionary. ... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... // H00-H59 - Diseases of the eye and adnexa (H00-H06) Disorders of eyelid, lacrimal system and orbit (H00) Hordeolum and chalazion (H000) Hordeolum and other deep inflammation of eyelid (H001) Chalazion (H01) Other inflammation of eyelid (H010) Blepharitis (H011) Noninfectious dermatoses of eyelid (H02) Other disorders of eyelid (H020) Entropion... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... Image File history File links Floaters. ... Image File history File links Floaters. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... A human eye Eyes are organs of vision that detect light. ... Vitreous humour is the clear aqueous solution that fills the space between the lens and the retina of the vertebrate eyeball. ... For other uses, see Embryo (disambiguation). ... This does not cite any references or sources. ... Entoptic phenomena are visual effects whose source is within the eye itself. ... The term visual field is sometimes used as a synonym to field of view, though they do not designate the same thing. ...

Latin-derived Muscae volitantes (meaning 'flying flies'), or French-derived mouches volantes, are a specific type of floater consisting of small spots whose presence is normal and attributed to minute remnants of embryonic structures in the vitreous humour.^[1]

Description

Floaters are suspended in the vitreous humour, the thick fluid or gel that fills the eye. Thus, they generally follow the rapid motions of the eye, while drifting slowly within the fluid. When they are first noticed, the natural reaction is to attempt to look directly at them. However, attempting to shift one's gaze toward them can be difficult since floaters follow the motion of the eye, remaining to the side of the direction of gaze. Floaters are, in fact, visible only because they do not remain perfectly fixed within the eye. Although the blood vessels of the eye also obstruct light, they are invisible under normal circumstances because they are fixed in location relative to the retina, and the brain "tunes out" stabilized images due to neural adaptation. This does not occur with floaters and they remain visible. Neural adaptation or sensory adaptation is a change over time in the responsiveness of the sensory system to a constant stimulus. ...

Floaters are particularly noticeable when looking at a blank surface or an open monochromal space, such as blue sky. Despite the name "floaters", many of these specks have a tendency to sink toward the bottom of the eyeball, in whichever way the eyeball is oriented; the supine position tends to concentrate them near the fovea, which is the center of gaze, while the textureless and evenly lit sky forms an ideal background against which to view them.

Floaters are not uncommon, and do not cause problems for most people. However, floaters are more than a nuisance and a distraction to those with severe cases, especially if the spots seem to constantly drift through the field of vision. The shapes are shadows projected onto the retina by tiny structures of protein or other cell debris discarded over the years and trapped in the vitreous humour. Floaters can even be seen when the eyes are closed on especially bright days, when sufficient light penetrates the eyelids to cast the shadows. It is not, however, only elderly people who suffer from floaters; they can certainly become a problem to younger people, especially if they are myopic. They are also common after cataract operations or after trauma. In some cases, floaters are congenital. Human eye cross-sectional view. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Normal vision. ... The references in this article would be clearer with a different and/or consistent style of citation, footnoting or external linking. ... A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ...

Floaters have been known to catch and refract light in ways that somewhat blur vision temporarily until the floater moves to a different area. Many times they trick the sufferer into thinking they see something out of the corner of their eye that really is not there. Most sufferers are able to, with time, learn to ignore their floaters. For people with severe floaters it is nearly impossible to completely ignore the large masses that constantly stay within almost direct view. Some sufferers have noted a decrease in ability to concentrate while reading, watching television, walking outdoors, and driving, especially when tired.

Causes

There are various causes for the appearance of floaters, of which the most common are described here. Basically, any way by which material enters the vitreous humour is a cause for floaters.

Vitreous syneresis

The most common cause of floaters is shrinkage of the vitreous humour: this gel-like substance consists of 99% water and 1% solid elements. The solid portion consists of a network of collagen and hyaluronic acid, with the latter retaining water molecules. Depolymerization of this network makes the hyaluronic acid release its trapped water, thereby liquefying the gel. The collagen breaks down into fibrils, which ultimately are the floaters that plague the patient. Floaters caused in this way tend to be few in number and of a linear form. Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Tropocollagen triple helix. ... Hyaluronan (also called hyaluronic acid or hyaluronate) is a glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. ... An example of alkene polymerisation, in which each Styrene monomer units double bond reforms as a single bond with another styrene monomer and forms polystyrene. ... Fibril is a fine fiber approximately 1 nm in diameter. ...

Posterior vitreous detachments and retinal detachments

In time, the liquefied vitreous body loses support and its framework contracts. This leads to posterior vitreous detachment, in which the vitreous body is released from the sensory retina. During this detachment, the shrinking vitreous can stimulate the retina mechanically, causing the patient to see random flashes across the visual field, sometimes referred to as "flashers." The ultimate release of the vitreous sometimes makes a large floater appear, usually in the shape of a ring ("Weiss ring"). As a complication, part of the retina might be torn off by the departing vitreous body, in a process known as retinal detachment. This will often leak blood into the vitreous, which is seen by the patient as a sudden appearance of numerous small dots, moving across the whole field of vision. Retinal detachment requires immediate medical attention, as it can easily cause blindness. Both the appearance of flashes and the sudden onset of numerous small floaters warrant an ophthalmological investigation. A posterior vitreous detachment (PVD) is an ocular condition in which there is a separation of the vitreous humor from the retina. ... A phosphene is an entoptic phenomenon characterized by the sensation of seeing light. ... Retinal detachment is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. ... Blindness is the condition of lacking visual perception due to physiological or psychological factors. ...

Regression of the hyaloid artery

The hyaloid artery, an artery running through the vitreous humour during the foetal stage of development, regresses in the third trimester of pregnancy. Its disintegration can sometimes leave cell matter. The hyaloid artery is a branch of the ophthalmic artery, which is itself a branch of the carotid artery. ... “Unborn child” redirects here. ... A pregnant woman near the end of her term Pregnancy is the carrying of one or more offspring in an embryonal or fetal stage of development by female mammals, including humans, inside their bodies, between the stages of conception and birth. ...

Other common causes

Patients with retinal tears may experience floaters if red blood cells are released from leaky blood vessels, and those with a posterior uveitis or vitritis, as in toxoplasmosis, may experience multiple floaters and decreased vision due to the accummulation of white blood cells in the vitreous humour [1]. Retinal detachment is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. ... Human red blood cells Red blood cells are the most common type of blood cell and the vertebrate bodys principal means of delivering oxygen from the lungs or gills to body tissues via the blood. ... A scanning electron microscope image of normal circulating human blood. ...

Other causes for floaters include cystoid macular edema and asteroid hyalosis. The latter is an anomaly of the vitreous humour, where by 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. Macular edema occurs when fluid and protein deposits collect on or under the macula of the eye, causing it to thicken and swell. ... Asteroid hyalosis is a degenerative condition of the eye involving small white opacities in the vitreous humor. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Standard atomic weight 40. ...

Tear film debris

Sometimes the appearance of floaters has to be attributed to dark specks in the tear film of the eye. Technically, these are not floaters, but they do look the same from the viewpoint of the patient. People with blepharitis or a dysfunctional meibomian gland are especially prone to this cause, but ocular allergies or even the wearing of contact lenses can cause the problem. To differentiate between material in the vitreous humour of the eye and debris in the tear film, one can look at the effect of blinking: debris in the tear film will move quickly with a blink, while floaters are largely unresponsive to it. Tear film debris is diagnosed by eliminating the possibility of true floaters and macular degeneration. Blepharitis is inflammation of the eyelids. ... The Meibomian glands (Glandulae tarsales) are a special kind of sebaceous glands at the rim of the eyelids, where they are responsible for to supply sebum, an oily substance that prevents evaporation of the eyes tear film. ... A soft contact lens A contact lens (also known as contact, for short) is a corrective or cosmetic lens placed on the cornea of the eye atop the iris. ... Listen to this article ( info) in media player in browser This audio file was created from an article revision dated 2005-07-19, and may not reflect subsequent edits to the article. ...

Diagnosis

Floaters are often readily observed by a doctor with the use of an ophthalmoscope or slit lamp. However, if the floater is a small piece of debris and near the retina they may not be able to observe it even if it appears large to the sufferer. The ophthalmoscope, invented by Hermann von Helmholtz, is an instrument used to examine the eye. ... The slit-lamp examination looks at structures that are at the front of the eye (the anterior segment): The eyelid, the sclera (white outer structure of the eye), conjunctiva (membranes lining the eyelid and sclera surface), iris (colored part of the eye), natural crystalline lens, and the cornea (thin transparent...

Increasing background illumination or using a pinhole to effectively decrease pupil diameter may allow a person to obtain a better view of his or her own floaters. The head may be tilted in such a way that one of the floaters drifts towards the central axis of the eye. In the sharpened image the fibrous elements are more conspicuous. (If the pinhole is kept moving slowly in small circles, the same technique evokes an interesting entoptic effect known as the vascular figure, which is a view of the blood vessels within one's own eye.) Entoptic phenomena are visual effects whose source is within the eye itself. ...

Treatment

Normally, there is no treatment indicated. Vitrectomy may be successful in treating more severe cases,^[2] however, the procedure is typically not warranted in those with lesser symptoms due to the potential for complications as severe as blindness. Floaters may become less annoying as sufferers grow accustomed to them, even to the extent that they may no longer notice them. Vitreous humour is the clear gel that fills the eyeball, lying between the lens and the retina in the eye. ...

Another treatment is laser vitreolysis. In this procedure a YAG laser is focused onto the floater and in a quick burst vaporizes the structure into, presumably, a less dense and not as noticeable consistency. This procedure can be time consuming and there is no consensus as to how completely effective it is. One study found laser vitreolysis "to be a safe but only moderately effective primary treatment conferring clinical benefit in one third of patients".^[3] Experiment with a laser (US Military) In physics, a laser is a device that emits light through a specific mechanism for which the term laser is an acronym: Light Amplification by Stimulated Emission of Radiation. ... Yttrium aluminium garnet (YAG, Y3Al5O12) is a synthetic crystalline material of the garnet group, used as the active laser medium in various solid-state lasers. ...

References

See also

Wikiquote has a collection of quotations related to:

Floater

• Blue field entoptic phenomenon, alias Scheerer's phenomenon - tiny bright dots moving quickly in the visual field.
• Phosphene
• Synchysis scintillans

Image File history File links This is a lossless scalable vector image. ... Wikiquote is a sister project of Wikipedia, using the same MediaWiki software. ... The blue field entoptic phenomenon or Scheerers phenomenon is the appearance of tiny bright dots moving quickly along squiggly lines in the visual field, especially when looking into blue light (such as the sky). ... A phosphene is an entoptic phenomenon characterized by the sensation of seeing light. ... Synchysis scintillans is a degenerative condition of the eye resulting in liquified vitreous humor and the accumulation of cholesterol crystals within the vitreous. ...

External links

• Facts About Floaters At the National Eye Institute (NEI).
• - Vitreous Floaters Information
• Eye-Floaters.com - Home of the Eye and Floaters Information Resource
• Eye-Floaters.com - Living with Eye Floaters
• Floatbusters.com - My blogresource on eye floaters - email support, have a vent and learn some techniques :)
• My little page about big floaters
• Floater Talk
• Floatersworld
• Picture of the entoptic phenomenon: Vitreous Floaters (PDF file, requires an Acrobat Reader or plugin)