Hyperopia

Hypermetropia

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ICD-10	H52.0
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ICD-9	367.0
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Hyperopia or hypermetropia, is most commonly known as farsightedness or longsightedness, where objects are more visible at a further distance. Hyperopia occurs when light rays enter the eye and reach behind the retina and create a blurred object, instead of hitting directly on the retina to create a focused object. This defect can be attributed to the length of the eye, if it is too short, or the roundness of the lens, if it is not round enough, both causing the inability to focus on near objects. An extreme case of this defect of vision is the incapability to focus on objects at any distance. As an object moves towards the eye, the eye must increase its power to keep the image on the retina. If the power of the cornea and lens is insufficient, the image will appear blurred.

Hyperopia, and restoring of vision with convex lens

People with hyperopia can experience blurred vision, asthenopia or fatigue of the eye, and accommodative dysfunction or the inability of the eye lens to reshape in order to focus on near objects. In addition, a person may experience binocular dysfunction, amblyopia, better known as lazy eye, or even strabismus, where the eyes are misaligned and cannot focus on the same object at the same time, similar to cross-eyed.

Hyperopia is often confused with presbyopia , another condition that frequently causes blurry near vision. Presbyopia is a natural age-related process which causes people in their mid-40's to experience vision problems, namely to close objects. This occurs because the lens begins to harden and become less flexibile to adjust to focus objects up close, which is different from the cause of hyperopia which is due to the shape of the eye (Presbyopia). Presbyopia is also sometimes referred to as farsightedness, since in otherwise normally-sighted persons it makes it more difficult to focus on near objects than on far objects..

Causes and Symptoms of hyperopia

Hyperopia can be due to family history, and in some cases, can be outgrown due to the changing lens shape throughout the adolescent years (Hyperopia). In extreme cases, diseases such as retinopathy, a nonimflammatory retina disorder, can also help cause hyperopia <ref name="Retinopathy"> [Dictionary.com. Merriam-Webster's Medical Dictionary. Merriam-Webster, Inc. http://dictionary.reference.com/browse/retinopathy (accessed: October 06, 2007)]. Other examples include eye tumors and lens dislocation which may also attribute to hyperopia.

Depending on the severity of hyperopia, an invidual may experience a great number of symptoms to none at all. In extreme cases, close up and distant vision is impaired, where all objects are blurry. Other times objects are only out of focus for close by objects. Headaches, aching eyes, burning and eyestrain are the most common symptoms, especially when looking at objects up close. Children do not usually experience many symptoms. However, if a child continuously rubs his or her eyes, becomes cross-eyed or has estropia (one eye points inward), or loses interest in reading, these could all be signs that the child may have hyperopia and should be examined by an ophthalmologist (.

Classification of hyperopia

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

Classification by clinical appearance

• Simple hyperopia
• Pathological hyperopia
• Functional hyperopia

It also occurs when light entering the eye focuses behind the retina.

Diagnosis

Visual acuity is affected according to the amount of hyperopia, as well as the patient's age, visual demands, and accommodative ability.

Treatment

Causes of hyperopia are usually found in early childhood and in most cases a person outgrows such defects through normal adulthood development and lengthening of the eyeball (Farsightedness). Various eye care professionals, including ophthalmologists, optometrists, orthoptists, and opticians, are involved in the treatment and management of hyperopia. At the conclusion of an eye examination, an eye doctor may provide the patient with an eyeglass prescription for corrective lenses.

Minor amounts of hyperopia are sometimes left uncorrected, however, larger amounts may be corrected with convex lenses in eyeglasses or contact lenses. Convex lenses have a positive dioptric value, which causes the light to focus closer than its normal range.

Hyperopia is sometimes correctable with various refractive surgery procedures.

External links

• pupilEyes - Learn how Hyperopia happens
• DocShop.com - Hyperopia Treatments
• Scottish Sensory Centre - Medical Info on Hypermetropia
• Presbyopia
• Farsightedness
• [1]- Hyperopia
• Farsightedness-Hyperopia

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