Presbyopia

 

Presbyopia

Definition

Presbyopia is a common type of vision disorder that occurs as you age. It is often referred to as the aging eye condition. Presbyopia results in the inability to focus up close, a problem associated with refraction in the eye.

Source : National Eye Institute 

 

Organ

Presbyopia concerns that the lens loses its elasticity, the focus is not done so properly.

 

Symptoms

Initial symptoms may be difficulties with prolonged close-up work, with tiring (eyestrain) of the eyes. This may be worse in dim light. You may also notice problems if you look from a near object to a faraway one, particularly if you have been concentrating on something close by, for a while. This may progress to blurred vision when looking at objects close up, to double vision and to headaches.

Source : Patient

 

Frequency

Presbyopia is widespread in the United States. According to U.S. Census Bureau estimates, in 2014 more than 150 million Americans were age 40 and older, and the country is growing older: The median age reached 37.7 that year, up 2.4 years since 2000. This growing number of older citizens generates a huge demand for eyewear, contact lenses and surgery that can help presbyopes deal with their failing near vision.

More than a billion people in the world were presbyopic as of 2005, according to the World Health Organization, and 517 million of these did not have adequate correction with eyeglasses. In developing countries, glasses are available in urban areas, but in rural regions they are unavailable or expensive. This is unfortunate, because good near vision is important for literacy and for performing close-up work.

Source : All About Vision 

 

Causes

Presbyopia happens naturally in people as they age. The eye is not able to focus light directly on to the retina due to the hardening of the natural lens. Aging also affects muscle fibers around the lens making it harder for the eye to focus on up close objects. The ineffective lens causes light to focus behind the retina, causing poor vision for objects that are up close.

When you are younger, the lens of the eye is soft and flexible, allowing the tiny muscles inside the eye to easily reshape the lens to focus on close and distant objects.

Anyone over the age of 35 is at risk for developing presbyopia. Everyone experiences some loss of focusing power for near objects as they age, but some will notice this more than others.

Source : National Eye Institute 

 

Evolution

Presbyopia progresses rapidly to 55 years slows to 60, and stabilizes.

 

Prevention

There’s no proven technique for preventing presbyopia. The gradual decline of the ability to focus on near objects affects everyone. However, you can help protect your vision with these steps:

  • Get regular eye examinations.
  • Control chronic health conditions that could contribute to vision loss, such as diabetes or high blood pressure.
  • Wear sunglasses.
  • Wear protective eyeglasses when participating in activities that could result in eye injury.
  • Eat a healthy diet with foods containing antioxidants, vitamin A, and beta carotene.
  • Make sure you’re using the right strength of eyeglasses.
  • Use good lighting when reading.

Source : Health Line 

 

Diagnosis

Your eye doctor can diagnose presbyopia as part of a comprehensive eye examination. In addition to checking for other eye problems, he or she will determine your degree of presbyopia by using a standard vision test.

Source : AAO

 

Treatment

Presbyopia Treatment: Eyeglasses

Eyeglasses with bifocal or progressive addition lenses (PALs) are the most common correction for presbyopia. Bifocal means two points of focus: the main part of the spectacle lens contains a prescription for distance vision, while the lower portion of the lens holds the stronger near prescription for close work.

Progressive addition lenses are similar to bifocal lenses, but they offer a more gradual visual transition between the two prescriptions, with no visible line between them.

Reading glasses are another choice. Unlike bifocals and PALs, which most people wear all day, reading glasses typically are worn just during close work.

If you wear contact lenses, your eye doctor can prescribe reading glasses that you wear while your contacts are in. You may purchase readers over-the-counter at a retail store, or you can get higher-quality versions prescribed by your eye doctor.

 

Presbyopia Treatment: Contact Lenses

Presbyopes also can opt for multifocal contact lenses, available in gas permeable or soft lens materials. Another type of contact lens correction for presbyopia is monovision, in which one eye wears a distance prescription, and the other wears a prescription for near vision. The brain learns to favor one eye or the other for different tasks. But while some people are delighted with this solution, others complain of reduced visual acuity and some loss of depth perception with monovision.

 

Presbyopia Treatment: Surgery

Surgical options to treat presbyopia also are available. One example is Refractec Inc.'s conductive keratoplasty or NearVision CK treatment, which uses radio waves to create more curvature in the cornea for a higher "plus" prescription to improve near vision. The correction is temporary and diminishes over time. The procedure is performed on one eye only for a monovision correction.

LASIK also can be used to create monovision, in which one eye is corrected for near vision while the other eye is stronger for distance vision.

The Kamra inlay (AcuFocus), approved by the FDA in 2015, is surgically implanted just under the top layers of the cornea in one eye. It uses principles similar to how a camera works, controlling the amount of light entering your eye and increasing the range of what you see in focus.

Source : All About Vision 

Images

  The small print of an ingredients list is hard to read for a person with presbyopia

Pesto ingredients - blurred

Source© User:Colin / Wikimedia Commons, via Wikimedia Commons

 

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