{{short description|Eye condition in which light is focused behind instead of on the retina}} {{use dmy dates|date=February 2025}} {{redirect-distinguish-text|Hyperopia|Hyperepia, a moth genus}} {{Infobox medical condition (new) | name = Hyperopia | synonyms = Hypermetropia, hyperopia, longsightedness, long-sightedness<ref name=pat/> | image = Hypermetropia color.svg | caption = Far-sightedness without (top) and with lens correction (bottom) | field = Ophthalmology, optometry | symptoms = Near blur, Distance and near blur, Asthenopia<ref name="Khurana-Opt" /> | complications = Accommodative dysfunction, binocular dysfunction, amblyopia, strabismus<ref name=AOA2008/> | onset = | duration = | types = | causes = Axial length of eyeball is too short, lens or cornea is flatter than normal, aphakia<ref name="Khurana-Opt" /> | risks = Ageing, hereditary<ref name="Khurana-Opt" /> | diagnosis = Eye exam | differential = Amblyopia, retrobulbar optic neuropathy, retinitis pigmentosa sine pigmento<ref name=Pet2014/> | prevention = | treatment = Eyeglasses, contact lenses, refractive surgeries, IOL implantation<ref name="Khurana-Opt" /> | medication = | prognosis = | frequency = ~7.5% (US)<ref name=NIH2016Facts/> | deaths = }} <!-- Definition and symptoms --> '''Far-sightedness''', also known as '''long-sightedness''', '''hypermetropia''', and '''hyperopia''', is a condition of the eye where distant objects are seen clearly but near objects appear blurred. This blur is due to incoming light being focused behind, instead of on, the retina due to insufficient accommodation by the lens.<ref name="Parson">{{cite book |last1=Ramjit |first1=Sihota |title=Parsons' diseases of the eye |last2=Radhika |first2=Tandon |date=15 July 2015 |publisher=Elsevier |isbn=978-81-312-3818-9 |edition=22nd |chapter=Refractive errors of the eye}}</ref> Minor hypermetropia in young patients is usually corrected by their accommodation, without any defects in vision.<ref name="Khurana-Opt">{{cite book |last1=Khurana |first1=AK |title=Theory and practice of optics and refraction |date=September 2008 |publisher=Elsevier |isbn=978-81-312-1132-8 |edition=2nd |pages=62–66 |chapter=Errors of refraction and binocular optical defects}}</ref> But, due to this accommodative effort for distant vision, people may complain of eye strain during prolonged reading.<ref name="Khurana-Opt"/><ref name="Artal">{{cite book |last1=Pablo |first1=Artal |title=Handbook of visual optics-Fundamentals and eye optics and |publisher=CRC Press |year=2017 |isbn=978-1-4822-3785-6}}</ref> If the hypermetropia is high, there will be defective vision for both distance and near.<ref name="Khurana-Opt" /> People may also experience accommodative dysfunction, binocular dysfunction, amblyopia, and strabismus.<ref name="AOA2008">{{cite web |last1=Moore |first1=Bruce D. |last2=Augsburger |first2=Arol R. |last3=Ciner |first3=Elise B. |last4=Cockrell |first4=David A. |last5=Fern |first5=Karen D. |last6=Harb |first6=Elise |date=2008 |title=Optometric Clinical Practice Guideline: Care of the Patient with Hyperopia |url=http://www.aoa.org/documents/CPG-16.pdf |archive-url=https://web.archive.org/web/20060717040622/http://www.aoa.org/documents/CPG-16.pdf |archive-date=2006-07-17 |access-date=2006-06-18 |website=American Optometric Association |pages=2–3, 10–11}}</ref> Newborns are almost invariably hypermetropic, but it gradually decreases as the newborn gets older.<ref name="Parson" />
<!-- Cause and diagnosis --> There are many causes for this condition. It may occur when the axial length of eyeball is too short or if the lens or cornea is flatter than normal.<ref name="Khurana-Opt" /> Changes in refractive index of lens, alterations in position of the lens or absence of lens are the other main causes.<ref name="Khurana-Opt" /> Risk factors include a family history of the condition, diabetes, certain medications, and tumors around the eye.<ref name=NIH2016Facts/><ref name=Pet2014/> It is a type of refractive error.<ref name=NIH2016Facts/> Diagnosis is based on an eye exam.<ref name="NIH2016Facts">{{cite web |date=July 2016 |title=Facts About Hyperopia |url=https://nei.nih.gov/health/errors/hyperopia |archive-url=https://web.archive.org/web/20170708062136/https://nei.nih.gov/health/errors/hyperopia |archive-date=8 July 2017 |access-date=11 July 2017 |website=NEI |language=en}}</ref>
<!-- Prevention and treatment --> Management can occur with eyeglasses, contact lenses, or refractive corneal surgeries.<ref name="Khurana-Opt" /> Glasses are easiest while contact lenses can provide a wider field of vision.<ref name="Khurana-Opt" /> Surgery works by changing the shape of the cornea.<ref name=NIH2016Facts/> Far-sightedness primarily affects young children, with rates of 8% at 6 years old and 1% at 15 years old.<ref name="Cas2014">{{Cite journal |last1=Castagno |first1=VD |last2=Fassa |first2=AG |last3=Carret |first3=ML |last4=Vilela |first4=MA |last5=Meucci |first5=RD |date=23 December 2014 |title=Hyperopia: a meta-analysis of prevalence and a review of associated factors among school-aged children. |journal=BMC Ophthalmology |volume=14 |page=163 |doi=10.1186/1471-2415-14-163 |pmc=4391667 |pmid=25539893 |doi-access=free}}</ref> It then becomes more common again after the age of 40, known as presbyopia, affecting about half of people.<ref name="Pet2014">{{cite book |last1=Kaiser |first1=Peter K. |url=https://books.google.com/books?id=g8U0AwAAQBAJ&pg=PA541 |title=The Massachusetts Eye and Ear Infirmary Illustrated Manual of Ophthalmology E-Book |last2=Friedman |first2=Neil J. |last3=II |first3=Roberto Pineda |date=2014 |publisher=Elsevier Health Sciences |isbn=978-0-323-22527-4 |page=541 |language=en |archive-url=https://web.archive.org/web/20170908192032/https://books.google.com/books?id=g8U0AwAAQBAJ&pg=PA541 |archive-date=2017-09-08 |url-status=live}}</ref> The best treatment option to correct hypermetropia due to aphakia is IOL implantation.<ref name="Khurana-Opt" />
Other common types of refractive errors are near-sightedness, astigmatism, and presbyopia.<ref name="NIH2010">{{Cite web |date=October 2010 |title=Facts About Refractive Errors |url=https://nei.nih.gov/health/errors/errors |archive-url=https://web.archive.org/web/20160728000730/https://nei.nih.gov/health/errors/errors |archive-date=28 July 2016 |access-date=30 July 2016 |website=National Eye Institute}}</ref>
==Signs and symptoms== In young patients, mild hypermetropia may not produce any symptoms.<ref name="Khurana-Opt" /> The signs and symptoms of far-sightedness include blurry vision, frontal or fronto temporal headaches, eye strain, tiredness of eyes, etc.<ref name="Khurana-Opt" /> The common symptom is eye strain. Difficulty seeing with both eyes (binocular vision) may occur, as well as difficulty with depth perception.<ref name="pat"/> The asthenopic symptoms and near blur are usually seen after close work, especially in the evening or night.<ref name="Parson" />
===Complications=== Far-sightedness can have rare complications such as strabismus and amblyopia. At a young age, severe far-sightedness can cause the child to have double vision as a result of "over-focusing".<ref>{{Cite web |date=2014-07-09 |title=Complications of long-sightedness |url=http://www.nhs.uk/Conditions/Long-sightedness/Pages/Complications.aspx |archive-url=https://web.archive.org/web/20160305225225/http://www.nhs.uk/Conditions/Long-sightedness/Pages/Complications.aspx |archive-date=2016-03-05 |access-date=2016-02-26 |website=NHS Choices |publisher=National Health Service}}</ref>
Hypermetropic patients with short axial length are at higher risk of developing primary angle closure glaucoma, so routine gonioscopy and glaucoma evaluation is recommended for all hypermetropic adults.<ref name="Kanski" />
==Causes== Simple hypermetropia, the most common form of hypermetropia, is caused by normal biological variations in the development of eyeball.<ref name="Khurana-Opt" /> Aetiologically, causes of hypermetropia can be classified as: * Axial: Axial hypermetropia occur when the axial length of eyeball is too short. About 1 mm decrease in axial length cause 3 diopters of hypermetropia.<ref name="Khurana-Opt" /> One condition that cause axial hypermetropia is nanophthalmos.<ref name="Kanski">{{Cite book |last=John F. |first=Salmon |title=Kanski's clinical ophthalmology: a systematic approach |publisher=Elsevier |year=2020 |isbn=978-0-7020-7713-5 |edition=9th |location=Edinburgh |oclc=1131846767}}</ref> * Curvatural: Curvatural hypermetropia occur when curvature of lens or cornea is flatter than normal. About 1 mm increase in radius of curvature results in 6 diopters of hypermetropia.<ref name="Khurana-Opt" /> Cornea is flatter in microcornea and cornea plana.<ref name="Kanski" /> * Index: Age related changes in refractive index (cortical sclerosis) can cause hypermetropia. Another cause of index hypermetropia is diabetes.<ref name="Khurana-Opt" /> Occasionally, mild hypermetropic shift may be seen in association with cortical or subcapsular cataract also.<ref name="Kanski" /> * Positional: Positional hypermetropia occur due to posterior dislocation of Lens or IOL.<ref name="Khurana-Opt" /> It may occur due to trauma.{{citation needed|date=January 2022}} * Consecutive: Consecutive hypermetropia occur due to surgical over correction of myopia or surgical under correction in cataract surgery.<ref name="Khurana-Opt" /> * Functional: Functional hypermetropia results from paralysis of accommodation as seen in internal ophthalmoplegia, CN III palsy etc.<ref name="Khurana-Opt" /> * Absence of lens: Congenital or acquired aphakia cause high degree hypermetropia.<ref name="Khurana">{{cite book |last1=Khurana |first1=AK |title=Comprehensive ophthalmology |publisher=Jaypee, The Health Sciences Publisher |year=2015 |isbn=978-93-86056-59-7 |edition=6th |pages=37–38 |chapter=Errors of refraction and accommodation}}</ref>
Far-sightedness is often present from birth, but children have a very flexible eye lens, which helps to compensate.<ref>{{Cite web |title=Normal, near-sightedness, and far-sightedness |url=https://www.medlineplus.gov/ency/imagepages/19511.htm |url-status=live |archive-url=https://web.archive.org/web/20160305230733/https://www.nlm.nih.gov/medlineplus/ency/imagepages/19511.htm |archive-date=2016-03-05 |access-date=2016-02-26 |website=MedlinePlus Medical Encyclopedia}}</ref> In rare instances, hyperopia can be due to diabetes, as well as problems with the blood vessels in the retina.<ref name="pat ">{{Cite web |last=Lowth |first=Mary |title=Long Sight (Hypermetropia) |url=http://patient.info/health/long-sight-hypermetropia |url-status=live |archive-url=https://web.archive.org/web/20160303133100/http://patient.info/health/long-sight-hypermetropia |archive-date=2016-03-03 |access-date=2016-02-26 |website=Patient |publisher=Patient Platform Limited}}</ref>
==Diagnosis== thumb|300px|Far-sighted vision on left, normal vision on right thumb|Human eye cross-section A diagnosis of far-sightedness is made by utilizing either a retinoscope or an automated refractor-objective refraction; or trial lenses in a trial frame or a phoropter to obtain a subjective examination. Ancillary tests for abnormal structures and physiology can be made via a slit lamp test, which examines the cornea, conjunctiva, anterior chamber, and iris.<ref name="nih2">{{Cite web |title=Farsightedness |url=https://www.medlineplus.gov/ency/article/001020.htm |url-status=live |archive-url=https://web.archive.org/web/20160224151749/https://www.nlm.nih.gov/medlineplus/ency/article/001020.htm |archive-date=2016-02-24 |access-date=2016-02-26 |website=MedlinePlus Medical Encyclopedia}}</ref><ref>{{Cite web |title=Slit-lamp exam |url=https://www.medlineplus.gov/ency/article/003880.htm |url-status=live |archive-url=https://web.archive.org/web/20160305235249/https://www.nlm.nih.gov/medlineplus/ency/article/003880.htm |archive-date=2016-03-05 |access-date=2016-02-26 |website=MedlinePlus Medical Encyclopedia}}</ref>
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 objects in detail.{{medical citation needed|date=February 2016}}
===Classification=== thumb|Choroid folds in high hyperopia (fluorescein angiography)
Hyperopia is typically classified according to clinical appearance, its severity, or how it relates to the eye's accommodative status.{{citation needed|date=January 2021}}
====Clinical classification==== There are three clinical categories of hyperopia.<ref name=AOA2008 /> * '''Simple hyperopia''': Occurs naturally due to biological diversity. * '''Pathological hyperopia''': Caused by disease, trauma, or abnormal development. * '''Functional hyperopia''': Caused by paralysis that interferes eye's ability to accommodate.
====Classification according to severity==== There are also three categories severity:<ref name=AOA2008 /> * '''Low''': Refractive error less than or equal to +2.00 diopters (D). * '''Moderate''': Refractive error greater than +2.00 D up to +5.00 D. * '''High''': Refractive error greater than +5.00 D.
====Components of hypermetropia==== Accommodation has significant role in hyperopia. Considering accommodative status, hyperopia can be classified as:<ref name="Artal" /><ref name="Khurana-Opt" /> * '''Total hypermetropia''': It is the total amount of hyperopia which is obtained after complete relaxation of accommodation using cycloplegics like atropine. * '''Latent hyperopia''': It is the amount of hyperopia normally corrected by ciliary tone (approximately 1 diopter). * '''Manifest hyperopia''': It is the amount of hyperopia not corrected by ciliary tone. Manifest hyperopia is further classified into two, facultative and absolute. ** '''Facultative hyperopia''': It is the part of hyperopia corrected by patient's accommodation. ** '''Absolute hyperopia''': It is the residual part of hyperopia which causes blurring of vision for distance.
So, Total hyperopia= latent hyperopia + manifest hyperopia (facultative + absolute)<ref name="Artal" />
==Treatment== ===Corrective lenses=== The simplest form of treatment for far-sightedness is the use of corrective lenses, i.e. eyeglasses or contact lenses.<ref>{{Cite report |url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0009653/ |title=Screening for Visual Impairment in Children Ages 1-5 Years: Systematic Review to Update the 2004 U.S. Preventive Services Task Force Recommendation |last1=Chou |first1=Roger |last2=Dana |first2=Tracy |last3=Bougatsos |first3=Christina |date=2011-02-01 |publisher=Agency for Healthcare Research and Quality |location=Rockville, MD |volume=81 |pmid=21542544 |archive-url=https://web.archive.org/web/20170908192033/https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0009653/ |archive-date=2017-09-08 |via=PubMed Health |section=Introduction |section-url=https://www.ncbi.nlm.nih.gov/books/PMH0009656/ |series=Evidence Syntheses}}</ref><ref>{{Cite web |author1=Pmhdev |title=Farsightedness (Hyperopia): Treatments |url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0023031/ |archive-url=https://web.archive.org/web/20170908192033/https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0023031/ |archive-date=2017-09-08 |access-date=2016-02-26 |website=PubMed Health |publisher=U. S. National Library of Medicine}}</ref> Eyeglasses used to correct far-sightedness have convex lenses.<ref name="nhs"/>
===Surgery=== There are also surgical treatments for far-sightedness:
'''Laser procedures''' * Photorefractive keratectomy (PRK): This is a refractive technique that is done by removal of a minimal amount of the corneal surface.<ref name="nhs">{{Cite web |title=Treating long-sightedness |url=http://www.nhs.uk/conditions/Long-sightedness/Pages/Treatment.aspx |archive-url=https://web.archive.org/web/20160305222557/http://www.nhs.uk/conditions/Long-sightedness/Pages/Treatment.aspx |archive-date=2016-03-05 |access-date=2016-02-26 |website=NHS Choices |publisher=National Health Service}}</ref><ref name="pub">{{Cite journal |last1=Settas |first1=George |last2=Settas |first2=Clare |last3=Minos |first3=Evangelos |last4=Yeung |first4=Ian Yl |date=2012-01-01 |title=Photorefractive keratectomy (PRK) versus laser assisted in situ keratomileusis (LASIK) for hyperopia correction |journal=Cochrane Database of Systematic Reviews |volume=6 |issue=6 |article-number=CD007112 |doi=10.1002/14651858.CD007112.pub3 |issn=1469-493X |pmc=7388917 |pmid=22696365}}</ref> Hyperopic PRK has many complications like regression effect, astigmatism due to epithelial healing, and corneal haze.<ref name="Lasik">{{cite web |last1=Gulani |first1=Arun C |date=9 November 2019 |title=LASIK Hyperopia: Background, History of the Procedure, Problem |url=https://emedicine.medscape.com/article/1221098-overview}}</ref> Post operative epithelial healing time is also more for PRK.<ref name="Khurana-RS">{{cite book |last1=Khurana |first1=AK |title=Theory and practice of optics and refraction |date=September 2008 |publisher=Elsevier |isbn=978-81-312-1132-8 |edition=2nd |pages=307–348 |chapter=Refractive surgery}}</ref> * Laser assisted in situ keratomileusis (LASIK): Laser eye surgery to reshape the cornea, so that glasses or contact lenses are no longer needed.<ref name=pub /><ref>{{Cite web |title=Laser Eye Surgery |url=https://www.medlineplus.gov/lasereyesurgery.html |url-status=live |archive-url=https://web.archive.org/web/20160306003502/https://www.nlm.nih.gov/medlineplus/lasereyesurgery.html |archive-date=2016-03-06 |access-date=2016-02-26 |website=MedlinePlus}}</ref> Excimer laser LASIK can correct hypermetropia up to +6 diopters.<ref name="Lasik" /> LASIK is contraindicated in patients with lupus and rheumatoid arthritis.<ref name="Lasik" /> * Laser epithelial keratomileusis (LASEK): Resembles PRK, but uses alcohol to loosen the corneal surface.<ref name=nhs /> * Epi-LASIK: Epi-LASIK is also used to correct hyperopia.<ref name="Khurana-RS"/> In this procedure, use of epikeratome eliminates the use of alcohol.<ref name="Khurana-RS"/> * Laser thermal keratoplasty (LTK): Laser thermal keratoplasty is a laser based non-destructive refractive procedure used to correct hyperopia and presbyopia.<ref name="Khurana-RS"/> It uses Thallium-Holmium-Chromium (THC): YAG laser.<ref name="Khurana-RS"/>
'''IOL implantation''' * Aphakia correction: High degree hypermetropia due to absence of lens (aphakia) is best corrected using intraocular lens implantation.{{citation needed|date=January 2021}} * Refractive lens exchange (RLE): A variation of cataract surgery where the natural crystalline lens is replaced with an artificial intraocular lens; the difference is the existence of abnormal ocular anatomy which causes a high refractive error.<ref>{{Cite journal |last1=Alió |first1=Jorge L. |last2=Grzybowski |first2=Andrzej |last3=Romaniuk |first3=Dorota |date=2014-12-10 |title=Refractive lens exchange in modern practice: when and when not to do it? |journal=Eye and Vision |volume=1 |page=10 |doi=10.1186/s40662-014-0010-2 |issn=2326-0254 |pmc=4655463 |pmid=26605356 |doi-access=free}} {{open access}}</ref> * Phakic IOL: Phakic intraocular lens are lenses that implanted inside eye without removing the normal crystalline lens. Phakic IOLs can be used to correct hypermetropia up to +20 diopters.<ref name="Khurana-RS"/>
'''Non laser procedures''' * Conductive keratoplasty (CK): Conductive keratoplasty is a non laser refractive procedure used to correct presbyopia and low hypermetropia (+0.75D to +3.25D) with or without astigmatism (up to 0.75D).<ref name="Khurana-RS" /><ref name="AAO-CK">{{cite web |title=Conductive Keratoplasty |url=https://eyewiki.aao.org/Conductive_Keratoplasty |website=eyewiki.aao.org}}</ref> It uses radiofrequency energy to heat and shrink corneal collagen tissue. CK is contraindicated in pregnant/breastfeeding women, central corneal dystrophies and scarring, history of herpetic keratitis, type 1 diabetes etc.<ref name="AAO-CK"/> * Automated lamellar keratoplasty (ALK): Hyperopic automated lamellar keratoplasty (H-ALK) and Homoplastic ALK are ALK procedures that corrects low to moderate hyperopia.<ref name=":0">{{Cite book |title=Refractive surgery |publisher=Mosby / Elsevier |others=Azar, Dimitri T. |year=2007 |isbn=978-0-323-03599-6 |edition=2nd |location=Philadelphia |oclc=853286620}}</ref> Poor predictability and the risk of complications limits usefulness of these procedures.<ref name=":0" /> * Keratophakia and epi-keratophakia are another two non laser surgical procedures used to correct hypermetropia.<ref name=":0" /> Keratophakia is a surgical technique developed by Barraquer for treating high hypermetropia and aphakia. Poor predictability and induced irregular astigmatism are complications of these procedures.<ref name=":0" />
==Etymology== The term ''hyperopia'' comes from Greek ὑπέρ ''hyper'' "over" and ὤψ ''ōps'' "sight" (<small>GEN</small> ὠπός ''ōpos'').<ref>{{cite web |title=hyperopia |url=http://www.etymonline.com/index.php?term=hyperopia |url-status=live |archive-url=https://web.archive.org/web/20170908192033/http://www.etymonline.com/index.php?term=hyperopia |archive-date=2017-09-08 |website=Online Etymology Dictionary |publisher=Douglas Harper}}</ref>
==References== {{Reflist}}
== External links == {{Scholia|topic}} * {{Commons inline}} {{Medical resources | ICD10 = {{ICD10|H|52|0|h|49}} | ICD9 = {{ICD9|367.0}} | DiseasesDB = 29644 | MedlinePlus = 001020 | MeSH = D006956 }} {{Eye pathology|pathways}} {{Portal bar|Medicine}} {{Authority control}}
Category:Disorders of ocular muscles, binocular movement, accommodation and refraction Category:Wikipedia medicine articles ready to translate Category:Wikipedia neurology articles ready to translate