Far-sightedness

Eye condition in which light is focused behind instead of on the retina

Far-sightedness
Synonyms	Hypermetropia, hyperopia, longsightedness, long-sightedness
Pronounce	N/A
Field	Ophthalmology, optometry
Symptoms	Near blur, Distance and near blur, Asthenopia
Complications	Accommodative dysfunction, binocular dysfunction, amblyopia, strabismus
Onset
Duration
Types
Causes	Axial length of eyeball is too short, lens or cornea is flatter than normal, aphakia
Risks	Ageing, heriditary
Diagnosis	Eye exam
Differential diagnosis	Amblyopia, retrobulbar optic neuropathy, retinitis pigmentosa sine pigmento
Prevention
Treatment	Eyeglasses, contact lenses, refractive surgeries, IOL implantation
Medication
Prognosis
Frequency	~7.5% (US)
Deaths

Also called hyperopia, is a common type of refractive error where distant objects may be seen more clearly than objects that are near.

Pathophysiology

Farsightedness develops in eyes that focus images behind the retina instead of on the retina, which can result in blurred vision.

Causes

Far-sightedness can occur when the eyeball is too short, which prevents incoming light from focusing directly on the retina. It may also be caused by an abnormal shape of the cornea or lens.

Risk factors

Farsightedness can affect both children and adults. It affects about 5 to 10 percent of Americans. People whose parents are farsighted may also be more likely to get the condition.

How do people perceive far-sightedness?

Some people may not notice any problems with their vision, especially when they are young.

Blurred vision

For people with significant farsightedness, vision can be blurry for objects at any distance, near or far.

Mechanism

• The cornea and lens bend (refract) incoming light rays so they focus precisely on the retina at the back of the eye.
• Refraction is the bending of light as it passes through one object to another.
• Vision occurs when light rays are bent (refracted) as they pass through the cornea and the lens.
• The light is then focused on the retina.
• The retina converts the light rays into messages that are sent through the optic nerve to the brain.
• The brain interprets these messages into the images we see.

Refractive errors

In refractive errors, the shape of the eye prevents light from focusing on the retina. The length of the eyeball (longer or shorter), changes in the shape of the cornea, or aging of the lens can all cause refractive errors.

Signs and symptoms

The symptoms of farsightedness vary from person to person. Your eye care professional can help you understand how the condition affects you. Common signs and symptoms of farsightedness include the following:

• Headaches
• Eyestrain
• Squinting
• Blurry vision, especially for close objects

Diagnosis

An eye care professional (Optometrists or Doctor of Optometry) as well eye physicians can diagnose farsightedness and other refractive errors during a comprehensive dilated eye examination.

Treatment / correction

Farsightedness can be corrected with eyeglasses, contact lenses, or refractive surgery.

Eye glasses

Eyeglasses are the simplest and safest way to correct farsightedness.

Contact Lenses

work by becoming the first refractive surface for light rays entering the eye, causing a more precise refraction or focus. In many cases, contact lenses may provide clearer vision, a wider field of vision, and greater comfort. They are a safe and effective option if fitted and used properly.

Refractive Surgery

Surgery aims to permanently change the shape of the cornea, which will improve refractive vision. Surgery can decrease or eliminate dependency on wearing eyeglasses and contact lenses. There are many types of refractive surgeries and surgical options should be discussed with an eye care professional.

External links

Classification	ICD-10: H52.0 DiseasesDB: 29644
External resources	MedlinePlus: 001020

Far-sightedness Resources
Latest articles Most recent articles Ongoing trials	Wikipedia