What is Presbyopia?
Presbyopia is a condition, caused by aging, in which people find it difficult to read small words at close distances or to work on the computer for long periods of time. The condition is sometimes called short arm syndrome, because sufferers must often push small print to an arm's length to be able to read it. When adults are in their forties, the lens of the eye begins to have difficulty accommodating, or in other words, changing its focusing distance. This is due to gradual a thickening of the lens that creates less flexibility.
Symptoms of presbyopia include difficulty in seeing contrasts between small bits of text, a need for greater lighting to read or do close work like sewing, and a feeling that the eyes are tired or strained after reading for short periods of time. Virtually all adults over forty experience some or all of the symptoms of presbyopia. Fortunately, a number a treatments for the condition exist. Wearing glasses, using contact lenses, or getting laser surgery can reduce the impact of presbyopia on one's life.
If another sight impairment is present, bifocal glasses will give those with presbyopia a way to address additional sight impairment in the top half of the lenses. Looking out of the bottom portion of the glasses will correct vision problems when reading or doing close work. There is a clear delineation to the wearer between the separate strengths of the lenses.
Progressive addition lenses are a newer type of bifocals without a clear line. As the eye scans up the lens of these glasses, the strength of the lens slowly changes. Progressive addition lenses are thought to be easier to wear and less disorienting, as one changes focus in stages instead of abruptly.
Those with presbyopia who do not have other sight problems may simply opt for reading glasses. The advantage of reading glasses is that they do not have to worn all the time, but can be used only when needed. Though the term reading glasses implies that these lenses are used for reading, they can also be used to focus on close-up work of any kind.
If glasses don't appeal, two types of contact lenses are available to correct presbyopia. Multifocal lenses work like bifocals, providing dual points of focus. Monovision lenses work very differently. One eye is fitted with a lens to address distance, while the other eye's contact lens is a completely different strength to address presbyopia. Some people do not like the feeling of monovision and feel nauseated or dizzy using these lenses. Since the eyes no longer have stereoscopic ability because of the different strength in lenses, depth perception can be negatively affected.
There are surgical alternatives to glasses and contact lenses. Lasik surgery techniques, with minimal downtime after surgery, produce a monovision effect. It's advisable that anyone considering Lasik try monovision lenses for a few weeks before undergoing permanent changes to the eyes through laser surgery.
In 2004, the FDA approved a new technique, conductive keratoplasty, for the treatment of presbyopia. In this surgery, radiofrequent energy shrinks the cornea, which results in the lens lengthening. This surgery has the same effects as Lasik, so those considering keratoplasty should be certain they can cope with monovision. If monovision proves to be an acceptable alternative for coping with presbyopia, the surgery itself only lasts three minutes and has a 98% success rate at the 12-month mark.
If one would like to try more natural methods of correcting presbyopia, there are a couple of suggestions. Many herbalists recommend taking the supplement lutein, which may prevent presbyopia in addition to providing overall eye health. Lutein is also abundant in green vegetables and egg yolks.
Some optometrists believe that eye exercises increase visual acuity and can decrease or eliminate presbyopia. Both of these natural methods offer anecdotal evidence to support their claims of success. However, neither taking lutein nor engaging in eye exercises has been scientifically proven to correct vision problems.
i have a problem in understanding the meaning of the disease presbyopia. in most of the books its given that presbyopia is a defect in which an old person cannot see nearby objects. this means the person is suffering from old age hypermetropia, but in most of the schools including my school the teachers have taught that presbyopia is a defect in which a person is not able to see nearby as well as far off objects. this means the person suffers from both myopia and hypermetropia. what is presbyopia?
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