แสดงบทความที่มีป้ายกำกับ Presbyopia แสดงบทความทั้งหมด
แสดงบทความที่มีป้ายกำกับ Presbyopia แสดงบทความทั้งหมด

วันอาทิตย์ที่ 20 กันยายน พ.ศ. 2552

Bifocal Contact Lenses For Presbyopia

Presbyopia is a vision in which they make clear the eyes are not in a position sharply on close objects. It usually begins after the age of about forty years ago, when you restart the lenses into the eye reduce the flexibility. Presbyopia affects about 90 million adults in the U.S. alone and about one quarter of patients will be through the door an ophthalmologist suffer.

Symptoms of presbyopia have difficulty reading, difficulty seeing in low light conditions and sometimesHeadaches.

Typically, these problems have been addressed with vision to be the old-fashioned reading glasses. Or existing eyeglass wearers can opt for bifocal eyeglasses. However, the use of modern contact lenses for use with presbyopia has some distinct advantages over their cosmetic appeal. For example, they can also suitable for other aspects of lifestyle, a carrier such as sports, exercise, or the use of a computer.

Recently, contact lensesfor the correction of presbyopia have conveniently types such as disposable or frequent replacement types. Today, these are very popular lens types are obvious advantages for the wearer.

HOW lenses to correct presbyopia

From a technical perspective, there are three different ways, can be used by the contact lenses to correct presbyopia, each with advantages and disadvantages for certain patients. ButIt is important that there is a choice, and each carrier is probably a method best suited to their unique situation are. The various methods of contact lenses are as follows:

Monovision

The monovision technique with one eye a lens for seeing near objects, and in the other eye, a lens to see distant objects. Many people find that monovision works very well for them. It relies on the ability of the brain, from process and to combine specific informationthe best available sources to deliver the clearest possible vision. In some cases, the ophthalmologist may employ a Bifocal lens in one eye and a normal distance lens in the other. The main problem associated with monovision is the apparent loss of depth of vision in some patients.

BIFOCAL CONTACT LENSES

As with traditional bifocal eyeglasses, each lens in bifocal contact lenses have two powers - one for seeing near objectsother for distant objects. Some types of bifocal lenses when magnified look a little like a cross with a central inner zone surrounded by the outer zone. The disadvantage of this type of lens that could, under certain conditions in the reduced lighting, the vision is not always as sharp in certain areas.

MULTIFOCAL LENSES

Multifocal contact lenses work very much like the progressive lenses for eyeglasses. These lenseshave several zones of different power to support the eye, as after the focus changes to different objects at different distances. Therefore, these lenses are designed for the vision at near, intermediate and distant objects work. Its disadvantages are generally the same as for bifocal contact lenses, with occasional loss of visual acuity.

Bifocal lenses are translating into two basic design types are available, "and" simultaneous ", theessential characteristics, as follows:

TRANSLATE bifocal lenses

Another name for the translation of lens is an "interaction lens". Regular gas permeable bifocal lenses of this type. Their use is very similar to the traditional bifocal eyeglasses. The carrier is through a zone for distance then look to "translate" to look through the other zone for the close. Both zones are not seen by the sameTime.

SIMULTANEOUS bifocal lenses

The majority of bifocal soft contact lenses on the market by the concurrent "type. As the name implies, actually, while the lens wearer sees through the various powers of the lenses at the same time. What happens is that the brain steps and suppressed "power and powers that are not necessary at this particular time in order to see clearly. There are other subdivisions of this lens type, but we do not go into details in this brief overview.

As with all contact lens selection and wear, choosing the right type of Bifocal lens depends as much on unique lifestyle of the wearer when his unique vision characteristics. For example, a patient who is regularly required to sports different needs, only one needs to have socially wear or for use in the workplace.

But the success of the adoption of bifocal contact> Lenses is very much on the expectations of the institution who should know that almost by definition, bifocal lenses much a compromise, and that he or she will never be the visual acuity in all environments and again that they had when younger. In most cases this is perfectly acceptable, and bifocal lenses have now earned their place in the ophthalmologist's ever-expanding repertoire.



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วันเสาร์ที่ 19 กันยายน พ.ศ. 2552

Contact Lenses to Correct Presbyopia - Bifocals & Multifocals

If you notice that you have started to move books and newspapers, further away from the eyes to correct on what you have to concentrate to read, chances are that you have developed presbyopia. Primarily, this is a common eye disease that usually affects people in their forties, their eyes lose elasticity, and makes it difficult to switch between the near and distant objects. Luckily, presbyopia is not at all dangerous, and most sufferers can be helped bifocal contact> Lenses.

Bifocal contact lenses come in soft or gas permeable materials and wear for daily or extended to. The most common are the two-week Acuvue bifocals. Bifocals would would sometimes also used as a multifocal, in this case, the word to distinguish each type of lens that comes with more than a power referred to. Technically, however, Bifocal contact lenses are always two forces for each eye, while multifocal have more thantwo.

Simultaneous vision lenses need your eyes by both powers Watch at any time, learn to choose an appropriate force for a situation. They come either with so-called concentric ring design, or as asph, the former contains a recipe in the center and others around him. RGP concentric are usually from mid-distance design, which means that the distance between them which are in the center of the lens, and soft bifocals mostdesigned to allow mid-close. Aspheric bifocal contact lenses are more like progressive eyeglass lenses, as they blended the two powers over the lens to have.

The other type of bifocal contact lenses is translated, or alternating vision lenses. This means that students between the two powers, depending on where one alternates. For this to work, the lens needs to be able to stay at any time, which is usually on your lower eyelid and ensuredthanks to a much smaller diameter than other lenses.

If your optician believes that you could benefit from wearing bifocal lenses, they see your 'add' prescribing and measure your students to decide what type of lens may be appropriate. A student can affect a large aspherical lens. There are other options for presbyopic, you should bifocal contact lenses difficult to. Monovision lenses is aAlternative that wearing your area prescription, which is connected in one eye and the desired route power on the other side. Thanks to modern technology, including makers, which are found in the past bifocals frustrating now in a position to bear them and get the almost perfect vision.



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