WordNet

to an advanced stage or point; "a young man who will go very far"
at or to a certain point or degree; "I can only go so far before I have to give up"; "how far can we get with this kind of argument?"
at or to or from a great distance in space; "he traveled far"; "strayed far from home"; "sat far away from each other"
being of a considerable distance or length; "a far trek"
being the animal or vehicle on the right or being on the right side of an animal or vehicle; "the horse on the right is the far horse"; "the right side is the far side of the horse"
beyond a norm in opinion or actions; "the far right"
located at a great distance in time or space or degree; "we come from a far country"; "far corners of the earth"; "the far future"; "a far journey"; "the far side of the road"; "far from the truth"; "far in the future"
remote in time; "if we could see far into the future"; "all that happened far in the past"
to a considerable degree; very much; "a far far better thing that I do"; "felt far worse than yesterday"; "eyes far too close together"
the syllable naming the fourth (subdominant) note of the diatonic scale in solmization

PrepTutorEJDIC

《距離》『遠くに』,遠くへ,はるかに / 《時間》『ずっと後まで(に),ずっと先まで(に)』 / 《程度》《形容詞・副詞[句],およびその比較級を修飾して》『ずっと』,はるかに(much),たいそう / 《おもに文・詩》(場所が)『遠くにある』,遠い / (二つのうち)『遠いほうの』,向こう側の / 長距離(長時間)にわたる / (政治的に)極端な
ファ(全音階の第4音)
farad / forte

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/07/23 16:55:45」(JST)

wiki en

Hyperopia or hypermetropia, commonly known as farsightedness (American English) or longsightedness ^[1](British English), is a defect of vision caused by an imperfection in the eye (often when the eyeball is too short or the lens cannot become round enough), causing the eye to not have enough power to see close or nearby objects.^[2] Correction is usually achieved by the use of convex corrective lenses. For near objects, the eye has to accommodate even more. Depending on the amount of hyperopia and the age of the person which directly relates to the eye's accommodative ability, the symptoms can be different.^[1]

People with hyperopia can experience blurred vision, asthenopia, accommodative dysfunction, binocular dysfunction, amblyopia, and strabismus,^[3]

Classification

Hyperopia is typically classified according to clinical appearance, its severity, or how it relates to the eye's accommodative status.^[3]

Simple hyperopia
Pathological hyperopia
Functional hyperopia

Signs/symptoms

The signs and symptoms of farsightedness are blurry vision, headaches, and eyestrain.^[2] The common symptom is 'tiring' of the eyes (asthenopia). Difficulty seeing with both eyes (binocular vision) may occur, as well as, difficulty with depth perception.^[1]

Causes

Human eye cross-section

The defect of hyperopia is the result of the visual image being focused behind the retina, hyperopia is mainly caused by two reasons:^[2]

Low converging power of eye lens because of weak action of ciliary muscles.
Abnormal shape of the cornea

Farsightedness is often present from birth, but children have a very flexible eye lens, which helps make up for the problem.^[4] In rare instances hyperopia can be due to diabetes, and problems with the blood vessels in the retina.^[1]

Diagnosis

Retina section

The diagnosis of farsightedness (hyperopia) can be done via the silt-lamp test which examines the cornea, conjunctiva, and iris, a yellow dye is used to help examine the cornea.^[5]^[6] Other test done include the following:^[5]

Glaucoma test
Refraction testing
Retinal exam
Eye movement
Visual acuity

In severe cases of hyperopia from birth, the brain has difficulty in merging the images that each individual eye sees. This is because the images the brain receives from each eye are always blurred. A child with severe hyperopia can never see objects in detail. If the brain never learns to see objects in detail, then there is a high chance of one eye becoming dominant. The result is that the brain will block the impulses of the non-dominant eye. In contrast, the child with myopia can see objects close to the eye in detail and does learn at an early age to see detail in objects.^{[medical citation needed]}

Treatment

Treatment of farsightedness includes contact lenses and eyeglasses,^[7]^[8] and can also be done via the following methods:

PRK: removal of a minimal amount of the corneal surface ^[9]^[10]
LASIK: laser eye surgery can fix an individuals vision,by reshaping the cornea, therefore glasses or contact lenses are not needed anymore.^[10]^[11]
Refractive Lens Exchange: is a variation of cataract surgery, the difference is the existence of abnormal ocular anatomy which causes a high refractive error.^[12]
LASEK resembles PRK, but uses alcohol to loosen the corneal surface.^[9]

Complications

Farsightedness can have rare complications such as strabismus and amblyopia, at a young age severe long-sightedness can cause the child to have double vision as a result of over-focusing^[13]

References

^ ^a ^b ^c ^d "Long Sight - Hypermetropia. Causes of longsightedness | Patient". Patient. Retrieved 2016-02-26.
^ ^a ^b ^c "Facts About Hyperopia | National Eye Institute". nei.nih.gov. Retrieved 2016-02-26.
^ ^a ^b American Optometric Association. Optometric Clinic ef_error_pres.htm "Refractive Error and Presbyopia." Refractive Source.com Accessed September 20, 2006.
^ "Normal, nearsightedness, and farsightedness: MedlinePlus Medical Encyclopedia Image". www.nlm.nih.gov. Retrieved 2016-02-26.
^ ^a ^b "Farsightedness: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. Retrieved 2016-02-26.
^ "Slit-lamp exam: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. Retrieved 2016-02-26.
^ Chou, Roger; Dana, Tracy; Bougatsos, Christina (2011-02-01). "Introduction". PubMed Health.
^ Information, National Center for Biotechnology; Pike, U. S. National Library of Medicine 8600 Rockville; MD, Bethesda; Usa, 20894. "Farsightedness (Hyperopia): Treatments - National Library of Medicine". PubMed Health. Retrieved 2016-02-26.
^ ^a ^b Choices, NHS. "Long-sightedness - Treatment - NHS Choices". www.nhs.uk. Retrieved 2016-02-26.
^ ^a ^b Settas, George; Settas, Clare; Minos, Evangelos; Yeung, Ian Yl (2012-01-01). "Photorefractive keratectomy (PRK) versus laser assisted in situ keratomileusis (LASIK) for hyperopia correction". The Cochrane Database of Systematic Reviews 6: CD007112. doi:10.1002/14651858.CD007112.pub3. ISSN 1469-493X. PMID 22696365.
^ "Laser Eye Surgery: MedlinePlus". www.nlm.nih.gov. Retrieved 2016-02-26.
^ Alió, Jorge L; Grzybowski, Andrzej; Romaniuk, Dorota (2014-12-10). "Refractive lens exchange in modern practice: when and when not to do it?". Eye and Vision 1. doi:10.1186/s40662-014-0010-2. ISSN 2326-0254. PMC 4655463. PMID 26605356.
^ Choices, NHS. "Long-sightedness - Complications - NHS Choices". www.nhs.uk. Retrieved 2016-02-26.

External links

"National Institutes of Health releases data from largest pediatric eye study | National Eye Institute". nei.nih.gov. Retrieved 2016-02-26.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 小児における屈折異常 refractive errors in children
2. 成人における視覚障害：屈折障害と老視 visual impairment in adults refractive disorders and presbyopia
3. レーザー屈折矯正手術 laser refractive surgery
4. 弱視の概要 overview of amblyopia
5. コンタクトレンズの概要 overview of contact lenses

English Journal

Changes in Axial Length and Refractive Error After Noninvasive Normalization of Intraocular Pressure From Elevated Levels.

Kim CS1, Kim KN2, Kang TS3, Jo YJ1, Kim JY1.
American journal of ophthalmology.Am J Ophthalmol.2016 Mar;163:132-139.e2. doi: 10.1016/j.ajo.2015.12.004. Epub 2015 Dec 14.
PURPOSE: To explore the changes in axial length and refractive error after noninvasive normalization of intraocular pressure (IOP) from elevated levels.DESIGN: A prospective observational study.METHODS: We enrolled 51 consecutive patients with abnormally elevated unilateral IOP (≥10 mm Hg compare
PMID 26701268

Eye growth and myopia development: Unifying theory and Matlab model.

Hung GK1, Mahadas K2, Mohammad F2.
Computers in biology and medicine.Comput Biol Med.2016 Mar 1;70:106-18. doi: 10.1016/j.compbiomed.2016.01.003. Epub 2016 Jan 12.
The aim of this article is to present an updated unifying theory of the mechanisms underlying eye growth and myopia development. A series of model simulation programs were developed to illustrate the mechanism of eye growth regulation and myopia development. Two fundamental processes are presumed to
PMID 26820446

Prevalence and causes of reduced visual acuity among children aged three to six years in a metropolis in China.

Pan CW1, Chen X2, Gong Y3, Yu J4, Ding H5, Bai J5, Chen J5, Zhu H2, Fu Z2, Liu H2.
Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists).Ophthalmic Physiol Opt.2016 Mar;36(2):152-7. doi: 10.1111/opo.12249. Epub 2015 Oct 2.
PURPOSE: To determine the prevalence and possible causes for reduced visual acuity (VA) in preschool children in a metropolis in China.METHODS: A school-based paediatric eye survey including 5862 preschool children aged three to 6 years was conducted from 2011 to 2012 in Yuhuatai District, Nanjing,
PMID 26432417

Japanese Journal

THE POSSIBILITY OF THE APPLICATION OF LOW REACTIVE LEVEL LASER THERAPY IN THE FIELD OF OPHTHALMOLOGY

LASER THERAPY 16(4), 189-197, 2007
NAID 130004553650

アイセル湖ポルダーにおける集落配置計画と中心地理論

地理学評論 79(11), 566-587, 2006
NAID 130003568647

Related Pictures

Hyperopia – (Far Sightedness) : PRK San Diego Questions – San Diego of Near and Far Sightedness on Vision Vision | Far Sighted | EyeGlass Guide How to Detect Far Sightedness: 3 Steps Astigmatism Myopia and Far-Sightedness Hyperopia Definition

★リンクテーブル★

リンク元	「遠視」
関連記事	「far」

「遠視」

Hyperopia
	Hyperopia lens correction
Classification and external resources
Specialty	Ophthalmology
ICD-10	H52.0
ICD-9-CM	367.0
DiseasesDB	29644
MedlinePlus	001020
MeSH	D006956
	[edit on Wikidata]

　　[★]

英: hyperopia, hypermetropia, far-sightedness
関: 近視

遠方視の状態で、網膜の後方に焦点がある場合。
+レンズで補正する必要がある。

臨床関連

緑内障：強い遠視では隅角が狭いことが多い。
調節性内斜視：
不同視弱視：不同視があり、なおかつ弱視眼が遠視の場合に起こりやすい。

「far」

　　[★] 　　　　　　　　　　

[pat-1] "Long Sight - Hypermetropia. Causes of longsightedness | Patient". Patient. Retrieved 2016-02-26.

[nih-2] "Facts About Hyperopia | National Eye Institute". nei.nih.gov. Retrieved 2016-02-26.

[AOA_Hyperopia-3] American Optometric Association. Optometric Clinic ef_error_pres.htm "Refractive Error and Presbyopia." Refractive Source.com Accessed September 20, 2006.

[4] "Normal, nearsightedness, and farsightedness: MedlinePlus Medical Encyclopedia Image". www.nlm.nih.gov. Retrieved 2016-02-26.

[nih2-5] "Farsightedness: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. Retrieved 2016-02-26.

[6] "Slit-lamp exam: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. Retrieved 2016-02-26.

[7] Chou, Roger; Dana, Tracy; Bougatsos, Christina (2011-02-01). "Introduction". PubMed Health.

[8] Information, National Center for Biotechnology; Pike, U. S. National Library of Medicine 8600 Rockville; MD, Bethesda; Usa, 20894. "Farsightedness (Hyperopia): Treatments - National Library of Medicine". PubMed Health. Retrieved 2016-02-26.

[nhs-9] Choices, NHS. "Long-sightedness - Treatment - NHS Choices". www.nhs.uk. Retrieved 2016-02-26.

[pub-10] Settas, George; Settas, Clare; Minos, Evangelos; Yeung, Ian Yl (2012-01-01). "Photorefractive keratectomy (PRK) versus laser assisted in situ keratomileusis (LASIK) for hyperopia correction". The Cochrane Database of Systematic Reviews 6: CD007112. doi:10.1002/14651858.CD007112.pub3. ISSN 1469-493X. PMID 22696365.

[11] "Laser Eye Surgery: MedlinePlus". www.nlm.nih.gov. Retrieved 2016-02-26.

[12] Alió, Jorge L; Grzybowski, Andrzej; Romaniuk, Dorota (2014-12-10). "Refractive lens exchange in modern practice: when and when not to do it?". Eye and Vision 1. doi:10.1186/s40662-014-0010-2. ISSN 2326-0254. PMC 4655463. PMID 26605356.

[13] Choices, NHS. "Long-sightedness - Complications - NHS Choices". www.nhs.uk. Retrieved 2016-02-26.

匿名

検索

案内

案内

far-sightedness