Longsightedness or Hypermetropia : Causes and treatment

Introduction – What is long-sightedness?

Longsightedness is also known as Hypermetropia. It is one type of refractive error or eye power. The others are Myopia and Astigmatism. Here one cannot see both distant objects as well as nearby objects clearly. Corrective lenses which correct this type of eye power are plus lenses. 

All newborns have hypermetropia or a plus eye power. As they grow a process of emmetropization occurs. In this process, the plus eye power reduces gradually to reach zero eye power.

What causes hypermetropia?

Hypermetropia occurs when the rays of light entering the eye meet behind the retina. The image of what the person sees is thus blurred. To see a clear image the rays of light must focus on the retina. This happens when the eyeball is shorter than what it should be or the parts of the eye which are responsible for bending the rays of light are not able to do so.

Following are the causes of hypermetropia

1. Hereditary
2. Prematurity
3. Hereditary
4. Flat cornea – The cornea is the front-most transparent layer of the eye
5. Lens defects which stop the lens from focussing the rays of light
6. Nanophthalmos – Here there is abnormal development of the eye

Types of Hypermetropia

Hyperopia can be classified in various ways

1. Significant hyperopia –  is defined as any degree of hyperopia sufficient to cause symptoms prompting clinical attention.
2. Simple hyperopia – is due to decreased axial length or decreased converging power of cornea, lens, and/or media (flattened cornea/decreased curvature, increased thickness of lens, etc.).
3. Pathologic hyperopia is due to atypical development, trauma, or disease of the eye (i.e. cataract, microphthalmia, nanophthalmos, aniridia, etc.).
4. Functional hyperopia is due to paralysis of accommodation. If affected, functional hyperopia is usually present at birth. Drugs, such as cycloplegics, can also cause transient hyperopia.

Hyperopia may also be categorized by the degree of refractive error:

1. Low hyperopia is +2.00D or less,
2. Moderate hyperopia ranges from +2.25 to +5.00D
3. High hyperopia is +5.25D or more. High hyperopia may be associated with blurring of the optic disk margin, known as pseudopapilledema. It can be differentiated from true papilledema by the presence of normal calibre vasculature and normal-appearing juxtaposed retina.

Hyperopia may also be classified by the role of accommodation to visual functioning.

1. Facultative hyperopia is hyperopia that can be overcome by accommodation
2. Absolute hyperopia cannot be overcome by accommodation.
3. Total hyperopia is the sum of Facultative and Absolute hyperopia.

Hyperopia may also be categorized based upon the outcome of non cycloplegic and cycloplegic refractions.

1. Manifest hyperopia is determined with non cycloplegic refraction whereas
2. Latent hyperopia is determined with cycloplegic refraction. The magnitude of hyperopia is the sum of Manifest and Latent hyperopia.

Hypermetropia diagnosis

Hypermetropia is a refractive error. We are able to diagnose hypermetropia during a routine eye examination. First, the vision or visual acuity is recorded. Then the eye power. The process of finding out the eye power is known as refraction. There are two ways one can find out the power

1. Autorefraction performed by an auto refractometer
2. Retinoscopy which is a manual process

In children when we check for eye power we have to put some eye drops which dilate the pupil. This help in the accurate measurement of eye power.

Symptoms of Hypermetropia?

Uncorrected farsightedness can have the following 

1. Normal vision and no symptoms – For small numbers children or adults may not have any complaints. In these patients it’s ok to not wear any glasses
2. Blurred vision
3. Headaches – 
4. Eye Strain
5. Unable to read the small print
6. Blurry distance vision. Initially nearby objects get blurry and then distant objects.

How is hypermetropia corrected?

Treatment options for Hypermetropia are either wearing glasses, contact lenses or Lasik (Laser eye surgery). The lenses are plus numbered lenses.

Hypermetropia treatments

Glasses

Plus lenses correct hypermetropia. They are also known as convex lenses. These prescription glasses help relieve most of the symptoms of hyperopia.

Contact lenses

Contact lenses can be worn instead of glasses. Unlike myopia, there are limited eye powers available for hypermetropia. There are 3 types of contact lenses. Daily, fortnightly and monthly disposable contact lenses.

Lasik or laser eye surgery

Refractive surgery is a surgical technique that gets rid of glasses. Unlike myopia where high eye powers can be corrected LASIK can correct smaller amounts of hypermetropia.

Pathological Hyperopia

In very high hyperopia one may consider getting a procedure called clear lens extraction. This is nothing but cataract surgery and here the natural lens of the eye is removed and replaced with an artificial lens. This gets rid of the need to wear high plus numbered lenses in glasses or contact lenses.

Complications of not treating hypermetropia

1. Headaches
2. Eye Strain
3. Blurry vision
4. Squints or strabismus – The type of strabismus is called accommodative esotropia and is usually associated with severe hyperopia.
5. Lazy eye or Amblyopia – This is a serious condition and may need amblyopia exercises to correct loss of vision.

Difference between hypermetropia and Presbyopia

In both these refractive errors one has to wear plus numbered lenses to see clearly. Presbyopia specifically refers to people needing glasses after the age of around 42 years of age to see things clearly. As the years add on this plus numer gradually increases.

Hypermetropia or long-sightedness on the other hand means even a child has to wear plus-numbered glasses to see clearly from both far and near.

Eye hospitals treating hypermetropia in Mumbai

One can safely say that all eye clinics and hospitals can treat hypermetropia. As mentioned earlier it is an eye power and forms the most basic part of an eye examination or consultation.

Eye solutions services

Eye Solutions is an eye hospital in Mumbai that is able to offer the entire range of treatments for Hypermetropia.  Our optometrists are postgraduates and have specialized in retinoscopy and pediatric refraction.