Farsightedness

In this article:

• What Is Farsightedness (Hyperopia)?
• Symptoms of Farsightedness
• When to see a doctor
• Adults
• Children and adolescents
• Causes of Farsightedness
• A refractive error cause
• Other refractive errors
• Complications
• Diagnosis
• Prevention
• References

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What Is Farsightedness (Hyperopia)?

Farsightedness is an eye vision condition meaning a person can see better in a far, and has low vision near. Hyperopia is a professional medical term for farsightedness, and means a refractive error is interfering with visual acuity.

By birth, human beings are predominantly hyperopic, and as the age progresses, hyperopic eyeballs grow to become emmetropic or even myopic. Hyperopia is a very common refractive condition in children and adults. The most common refractive error in childhood is farsightedness. If left untreated, it can cause multiple eye complications and poor performance at school.

Axial hyperopia, being the commonest, is usually present from birth. The prevalence of moderate hyperopia, i.e., ≥ +2 diopter at 6 and 12 years of age, is 13.2% and 5.0%, respectively, and it is more in White race individuals than in other ethnic groups.  For United States participants, non-Hispanic, and Hispanic White races have a significantly higher risk of hyperopia in 6 to 72 months of age group.

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Symptoms of Farsightedness

Depending on the age of presentation and the degree of hyperopia, clinical presentation varies from no symptom to a wide range of complaints. Age is an important factor not only due to the ability to express but also the accommodative effort of the patient.

Asymptomatic farsightedness. The patient’s inherent ciliary muscle tone and accommodative effort can overcome some degree of hyperopia without creating any difficulty. This type of hyperopia may be diagnosed by an ophthalmologist during an eye exam.

Symptomatic farsightedness:

• Deviation of eyes (noted by the parents) Parents sometimes note deviation of either or both eyes (simultaneous or alternative) in very young children with hyperopia. The commonest type is an inward crossed eye (esotropia).  
• Asthenopia: With total accommodative effort, the patient’s hyperopia is corrected here. In these cases, asthenopia (i.e., varied amount of tiredness of eyes with localized frontal/frontotemporal headache) is a very common symptom due to prolonged accommodative effort. Sometimes it may be associated with light sensitivity and tearing. Usually, asthenopia increases after near activity of long-duration.
• Dimness (blurriness) of vision. There will be dimness of vision if existing hyperopia is not corrected with accommodation. In hyperopia nearer objects focus behind the retina. Characteristically the defective vision affects near vision more than distant vision. Thus, the objects appear more blurred as they come closer.
• Sudden blurring of vision(intermittent). Due to prolonged accommodative effort (e.g., during reading), there may be an episode of accommodative spasm leading to a sudden blurring of vision, often termed as pseudo-myopia. It is commonly found in teenagers with uncorrected hyperopia. 

When to see a doctor

If you have noticed any vision problems in your child, or received a note from school about failed vision test, it is time to schedule an appointment with a pediatric ophthalmologist.

You may want to see an ophthalmologist if you have noticed you cannot see objects near, or visual activity causes headaches and tiredness.

It is a good idea to make yearly visual exams with an eye clinic to make sure you are not missing signs of worsening in your vision.

Adults

In the United States, for the ≥20 years age group, farsightedness is the least common refractive error while it was the most common refractive error with astigmatism in the ≥60 years age group. In Polish immigrants in Chicago, a study found that hyperopia is a more common refractive error overall and in the >45 years age group.

Children and adolescents

In 15 years or less age group, and ≥30 years age group, hyperopia is higher in females. A systematic review of refractive error revealed that the prevalence of hyperopia is 4% (less than myopia) in the population with more prevalence in school going boys than girls. 

In the 6 to 15 years age group in Cameroon, hyperopia is the most common refractive error. Hyperopia is unrelated to posterior subcapsular cataracts but is related to incident nuclear and cortical cataract. The intelligence quotient score in patients with farsightedness was lower than that of myopic in a study conducted in the United Kingdom. A higher prevalence of hyperopia is seen in people living in rural areas compared to urban areas. Farsightedness tends to run in families with a history of accommodative esotropia and hyperopia, and 20% in infancy develop crossed eyes (strabismus).

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Causes of Farsightedness

Diseases that may be associated with farsightedness (hyperopia):

• Nanophthalmos
• Microphthalmos
• Aniridia
• 16p11.2 microdeletion
• Myelin regulatory factor gene (MYRF) mutation
• Cortical cataract (index hyperopia) 
• Aphakia (congenital or acquired) 
• Hyperglycemia 
• Diabetes mellitus; after prompt control of hyperglycemia in diabetes mellitus
• Prolonged space mission (due to retina and optic nerve head edema)
• Peripapillary pachychoroid syndrome (PPS) 
• Heimler syndrome
• Kenny syndrome
• Accommodation loss due to complete CN III nerve palsy or internal ophthalmoplegia or paralysis by cycloplegic drops, lorazepam (functional hyperopia)
• After silicone oil eye injection.
• Loeys-Dietz syndrome, Larsen syndrome
• Leber congenital amaurosis
• X-linked retinoschisis and senile retinoschisis

Farsightedness can also develop as a result of the surgery of the eye for vision correction or trauma.

A refractive error cause

Axial hyperopia (most common – simple hyperopia): It is due to shorter than needed eyeball. Genetic predisposition plays an important role. Retinal edema can cause a hyperopic shift. 1 mm decrease in eye length leads to 3 diopters of hyperopia. 

Curvature hyperopia: It is due to flattening of the cornea or the lens or both. A radius of curvature increase in 1 mm leads to 6 diopters of hyperopia.

Index hyperopia: It is due to the change in the refractive index of the crystalline lens, which occurs in old age or diabetics. The refractory index gradually increases from the center to the periphery.

Positional hyperopia or absence of the lens (aphakia) or ocular pathologic conditions: This condition occurs due to malposition or absence of the crystalline lens (congenital or acquired) or intraocular lens owing to the creation of an aphakic zone in refractive media. Post-traumatic or post-surgical aphakia is not an uncommon cause of hyperopia.

Other refractive errors

Farsightedness can be often associated with other refractive conditions such as astigmatism, cataract and myopia

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Complications

One of the most serious complications is amblyopia. Amblyopia is the leading cause of visual impairment in children and adults and is very common during childhood.

In one review these ocular conditions were found to be responsible for amblyopia in kids:

• hyperopia 
• astigmatism 
• anisometropia
• esotropia
• exotropia
• CNLDO

Parental education and counseling are very important, not only to early diagnosis and treatment of hyperopia but also to prevent strabismus and amblyopia development.

Proper use of glasses, along with patching and exercises for amblyopia treatment, requires the active involvement of the parents.

Regular follow-ups with an eye examination and refraction testing are essential.

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Diagnosis

Diagnosis is made by an ophthalmologist, and is based on careful history and eye exam.

Visual Acuity: It depends on the age at presentation, degree of accommodation, and status of the crystalline lens and posterior segment. In children, the vision may not be affected due to a full compensatory mechanism of accommodation, wich returns focus of the image to the retina. 

As the status of the eye is usually not complicated by cataract and retinal diseases in children, distant vision may be affected with high hyperopia, which cannot be corrected by the full range of accommodation. There may be a gross reduction of vision if amblyopia develops in unilateral or bilateral high hyperopia cases. 

Near vision may also be diminished in children with high hyperopia or in aged people where accommodation is partially or fully lost due to advanced age. An age-related farsightedness can make near vision very difficult for correction.

Diffuse light examination:Eyeball and cornea may appear smaller, especially in high hyperopia and in unilateral cases. Sometimes it may simulate enophthalmos. Anterior chamber (both central and peripheral) appears shallow, and the angle of the anterior chamber may appear narrow with a small pupil. 

Gonioscopy is indicated in all cases to rule out possible angle closure. Cortical cataracts may also be present in aged persons or young individuals with diabetes.

Fundoscopy:Fundoscopy reveals a small optic disc with a very small cup. Disc margins become blurred with overcrowding of blood vessels, sometimes termed as “pseudo-papillitis” or “pseudo-papilledema” if bilateral. Choroidal folds may be present. An increased reflex of retina named as “shot-silk appearance” is seen along with crowding of the nerve fiber layer. 

Examination of Latent / Manifest strabismus: In children having uncorrected hyperopia for a long duration, strabismus may be present: latent (-phoria) or manifest (-tropia). Extraocular movement is usuallyfull in all directions of gazes.

Retinoscopy/Refraction: In the modern era of automated refraction, retinoscopy has its importance while examining young children and bed-ridden patients. It’s a good practice to evaluate a child with suspected any refractive error with cycloplegic retinoscopy from a 1-meter distance as routine. 

Cycloplegia abolishes ciliary muscle tone and accommodation to reveal the actual status of refraction. With a streak retinoscope, under cycloplegia, different powered-spherical lenses are used to reach a neutralization point (full illumination of the fundus with no movement)  both in the horizontal and vertical axis. 

Accommodation is a dynamic factor in controlling the state of refraction, specifically in hyperopia. Depending on the accommodation, manifest hyperopia may subdivide into:

• Absolute hyperopia, which cannot be overcome by accommodative effort
• When a patient cannot see 20/20 without glasses, absolute hyperopia is denoted by the weakest plus lens with which the patient can see 20/20.
• Facultative hyperopia which can be overcome by accommodation

The manifest hyperopia is the sum of absolute and facultative hyperopia. Clinically, it is measured by the strongest plus (or convex) lens with which the patient can still maintain the maximum vision (20/20).

Latent hyperopia is due to the inherent ciliary muscle tone. Usually, the magnitude of latent hyperopia is 1D, but it is higher at an early age and gradually decreases as age progresses. Cycloplegic agents like atropine unmask this condition. This latent hyperopia causes asthenopia symptoms without dimness of distant vision. Cycloplegia is a must to elicit the amount of latent hyperopia in children.    

• Total hyperopia = Latent hyperopia + manifest hyperopia
• Manifest hyperopia = Absolute hyperopia + facultative hyperopia

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Prevention

No definite cause of hyperopia is identified to date. Genetic predisposition, along with family history, plays an important role. Inherited defects of the eye refractive system cannot be avoided. 

It is important to establish a continuity care with the pediatric ophthalmologist if you know that farsightedness runs in your family. A primary care pediatrician will refer you for an eye exam, if your child shows signs of poor vision or developmental problems.

It is important to correct farsightedness to ensure the vision is normal in a child. An optometrist will help you with the selection of the glasses or contact lens to correct eyesight.

Avoid all factors that can potentially cause eyestrain:

• Take frequent breaks when working on the computer
• Massage neck and shoulders to restore blood flow if studying for awhile
• Make sure you have ergo-dynamically controlled work place
• Avoid reading in a dim light
• Eat healthy food that has plenty of vitamins important for vision
• Exercise daily 
• Prevent obesity and diabetes

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References

Hyperopia. Majumdar S, Tripathy K.2021 Aug 1. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–.PMID: 32809551 Free Books & Documents. Review.

Visual Acuity. Daiber HF, Gnugnoli DM.2021 Jul 31. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–.PMID: 33085445 Free Books & Documents. Review.

Visual Acuity Change. Levenson JH, Kozarsky A.In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 111.PMID: 21250059 Free Books & Documents. Review.

Moderate hyperopia prevalence and associated factors among elementary school students. Castagno VD, Fassa AG, Vilela MA, Meucci RD, Resende DP. Cien Saude Colet. 2015 May;20(5):1449-58. [PubMed]

Intra- and inter- examiner repeatability of cycloplegic retinoscopy among young children. McCullough SJ, Doyle L, Saunders KJ. Ophthalmic Physiol Opt. 2017 Jan;37(1):16-23. [PubMed]

Ocular Refraction at Birth and Its Development During the First Year of Life in a Large Cohort of Babies in a Single Center in Northern Italy. Semeraro F, Forbice E, Nascimbeni G, Cillino S, Bonfiglio VME, Filippelli ME, Bartollino S, Costagliola C. Front Pediatr. 2019;7:539. [PMC free article] [PubMed]

Distribution of Refractive Errors among Healthy Infants and Young Children between the Age of 6 to 36 Months in Kuala Lumpur, Malaysia-A Pilot Study. Yahya AN, Sharanjeet-Kaur S, Akhir SM. Int J Environ Res Public Health. 2019 Nov 27;16(23) [PMC free article] [PubMed]

The epidemiology of early childhood hyperopia. Tarczy-Hornoch K. Optom Vis Sci. 2007 Feb;84(2):115-23. [PubMed]

Visual outcomes after spectacles treatment in children with bilateral high refractive amblyopia. Lin PW, Chang HW, Lai IC, Teng MC. Clin Exp Optom. 2016 Nov;99(6):550-554. [PubMed]

Long-term refractive outcomes in children with early diagnosis of moderate to high hyperopia. Strabismus Laiginhas R, Figueiredo L, Rothwell R, Geraldes R, Chibante J, Ferreira CC.. 2020 Jun;28(2):61-66. [PubMed]

Hyperopia is predominantly axial in nature. Strang NC, Schmid KL, Carney LG. Curr Eye Res. 1998 Apr;17(4):380-3. [PubMed]

Origins of Refractive Errors: Environmental and Genetic Factors. Harb EN, Wildsoet CF. Annu Rev Vis Sci. 2019 Sep 15;5:47-72. [PubMed]