Posts Tagged ‘presbyopia’
As the name indicates, bifocal reading glasses are glasses with two distinct optical powers. These glasses are usually prescribed for presbyopic individuals who also need a correction for myopia or astigmatism. Being popular nowadays, bifocal reading glasses can be dated back to around 1760, when the America statesman and investor Benjamin Franklin first developed them. Suffering presbyopia and nearsightedness, the great man thought it was really inconvenient to switch between two pairs of prescription glasses. Even if there are still serious historians suggesting that there were others who had preceded Franklin in the invention of bifocal reading glasses, Franklin is certainly among the first to wear bifocal glasses.
An original version of bifocal reading glasses was made of the most convex lenses for close viewing in the lower half of the lens and the least convex lenses on the upper half. In the early 20th century, a new design using two separate lenses cut in half and combined together was invented. However, such a design had long been associated with a number of complications such as fragileness. At the end of the 19th century, Dr. John developed the technology of lens fusing, with which the two separate half lenses could be fused together appropriately. Nowadays, the production of bifocal reading glasses is further different. Manufacturers of bifocals usually mold a reading segment into a primary lens. In addition, such a reading segment is available in a variety of shapes and sizes, offering customized versions for individuals with specific occupations. Currently, the most popular design is the D-segment with 28mm wide.
Even if there are some design variations of bifocal reading glasses, the basic style has remained untouched since the first pair. The upper section of a bifocal lens is for distance vision and the bottom part for viewing near objects. This fundamental design is based on the fact that most people will tilt their heads slightly upwards in order to see a distant object and downwards for a near focus. This basic design enables presbyopia folks to benefit from those bifocal reading glasses in a natural way. In fact, bifocal glasses are being enjoyed by a large number of individuals with both presbyopia and nearsightedness. Bifocal glasses are generally considered healthier for people’s eyes, because the eyes can always see through the correct prescription lens. It is estimated that approximately 4 million Americans develop presbyopia each year, most of which are between 35 and 50 years old.
Firmoo.com is the emerging online eyeglasses store selling high quality eyewear, such as prescription eyeglasses (single vision myopic glasses, reading glasses, bifocal and progressive eyeglasses etc.,), prescription sunglasses (with RX tinted lenses), prescription sports goggles. Firmoo guarantees lowest possible price in the market. Firmoo’s return and refund policy makes any purchase risk-free ones.
Article Source:http://www.articlesbase.com/vision-articles/an-overview-of-bifocal-reading-glasses-1763148.html
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If you are having difficulty in reading then you might be suffering from presbyopia. This fairly common vision disorder usually occurs with advancing years, in the patients’ 40s. Presbyopia is caused by the thickening and hardening of the lens of the eye.
Diagnosing the Need for Surgical Reversal of Presbyopia
Since Presbyopia is an age-related disease, it is nothing to get alarmed about. Try and see if you have all the symptoms and visit an ophthalmologist to decide the best method for surgical reversal of Presbyopia. You might need to go for presbyopia treatments if you:
* can’t read small print
* need to keep the material farther away to read it
* suffer eyestrain in reading
* can’t easily see the contrasts between small bits of texts
* ed increased light while doing reading or other works needing close look at objects
Types of Presbyopia Treatments
There are many Presbyopia treatments through which surgical reversal can be achieved. These include:
* Glasses: The use of corrective eye glasses, particularly progressive or bifocal lenses while reading is a common method of vision correction in this case. Single vision or focus glasses are usually prescribed just for the purpose of reading. These glasses will not help you see things across the room the way bifocals can.
* Contact Lenses: Some people prefer wearing contact lenses instead of corrective eye glasses due to their convenience. Interestingly, more and more people are opting for a ‘monovison’ setup where in one lens has correction for near sight while the other has correction for far sight. With both eyes open, vision is generally clear.
* Surgical Treatment: This is a permanent solution for presbyopia. These days, laser techniques such as Lasik are also used for surgical reversal of presbyopia.
Method of Surgical Reversal of Presbyopia
Lasik is the most common of all presbyopia treatments. In this method an incision is made and a flap is created in the cornea with the help of a surgical blade. Then laser is applied to remove the targeted tissue of the cornea to reshape it. The whole process takes just a few minutes and is quite painless.
If you are worried about your failing eyesight, you can consult the eye specialists at the Laser Eye Center of Silicon Valley. The center has the most modern equipment and one of the best treatment success rates in the state of California.
Laser Eye Center of Silicon Valley performs surgical reversal of presbyopia treatments that include laser presbyopia reversal, anterior cilliary sclerotomy and refractive lens exchange.
Article Source:http://www.articlesbase.com/vision-articles/surgical-reversal-of-presbyopia-1748320.html
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Bifocal glasses refer to those having one section that corrects for distant vision and another section that corrects for near vision and Benjamin Franklin is believed to be the one who invents bifocals.
The reason why it is called bifocal derives from its special designation of the two lenses of different convexes posited in respectively the lower and upper half of the frame. At the very beginning the two parts were just combined directly, resulting in a sharp switch for the wearing when s/he read something from the above or from the top. Later, to solve this problem, at the end of the 19th century, Louis de Wecker developed a method for fusing the sections of the lenses together.
Bifocals were originally invented for the elders to read, and then people think that only aging people require bifocals their development of presbyopia all the time, but this is a misconception. The fact is that bifocals are also suitable for those who develop a combination of nearsightedness and farsightedness. For them, the lenses posited in the lower half of the frame are for nearsightedness correction while the upper are for farsightedness correction. Therefore, when you find young friends around you wear bifocals, do not feel surprised.
Based on the same principle, bifocals can help correct any combination of two different eyesight conditions, for example, bifocals can help correct astigmatism that is present in combination with other refractive defects.
However, every coin has two sides, bifocals lead to discomfort for the sharp vision switch from the upper to the lower or in reverse as mentioned above. Some wearers may experience from headaches and even dizziness. For the computer users, they would probably experience muscle fatigue due to the unusual angle and constant movement of the head.
Fortunately, with the progress of relative researches on it, new models come into being, the trifocal glasses and progressive glasses. As their names self-explanatory, the former consist of three corrective lenses on each side of a pair of glasses, for a total of six lenses for a pair while the latter are characterized by a gradient of increasing lens power. Both of them work similarly to bifocals do, but they aim at reducing the sharpness between different corrective lenses so as to make wearers suffer from fewer headaches from strained eyes.
Those progresses are not enough, researchers are trying to make new materials to make better bifocals, and to discovery new technologies that may provide a method which can selectively adjust the optical power of a lens.
At last, I would like to remind you that if you find yourself a need to wear bifocal glasses, you can firstly consult with an optician, who is best to be licensed, for there are different types of bifocals. With her/his help, you can decide which type of is the one for you.
Firmoo.com is the emerging online optical store selling high quality eyewear, such as prescription eyeglasses (single vision myopic glasses, reading glasses, bifocal and progressive eyeglasses etc.,), prescription sunglasses (with RX tinted lenses), prescription sports goggles. Firmoo guarantees lowest possible price in the market. Firmoo’s return and refund policy makes any purchase risk-free ones.
Article Source:http://www.articlesbase.com/vision-articles/is-it-true-that-only-aging-people-require-bifocal-glasses-1726729.html
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Our eyes are vulnerable to some diseases as we age. When we are over forty, we may suffer from presbyopia; when we are over fifty, we may suffer from Age-related Macular Degeneration (AMD), which can always lead to irreversible blindness. Here we are going to introduce something about AMD and some methods of prevention. The mechanism of AMD is the blood vessels in our eyes may become very fragile and the blood flow into our eye tissues. The most direct result is blurriness as a result of macular degeneration. However, as the conditions get even worse, our eyes will be in complete blindness.
That’s to say; once the macular is damaged or thinned, our vision will be influenced. The reason is our retinas are protected by the macular pigment from coming light. The thinner our macular pigment is, the worse our eyes are.
In fact, some substances play very important role in the protection of our eyes. For example, Lutein is a very effective antioxidant substance than are very useful in the protection of macula.
The scientists have not found such a method currently that can be employed in the cure of Macula Degeneration. But prevention is much important than treatment. Some very common methods can be used for the prevention of such diseases. Following are they.
We should first know what AMD is and what the cause of it is. Some bad habits can reduce the density of macula pigment. Such as, smoking and drinking alcohol can be very irritating for the macula; working under too bright light, as the sun and computer, can also reduce the density of the pigment. As mentioned above that lutein is very effective antioxidant substance which can help slow the process of macula degeneration. In this sense, it is very essential for us to intake foods that are abundant with lutein.
In fact, other materials can also help to slow the process of AMD. Thus, we should intake more other vitamins and mineral, while ingesting lutein.
Some eye doctors recommend that there are four substances that are vital for the health of our eyes.
The first one is, no doubt, lutein that is a kind of very effective antioxidant substance. It is very nice for us to use some lutein pills that are extracted from marigold plant. It is true that these pills are expensive, but effective.
The matter of fragility in the blood vessels can also be prevented by taking Bilberry in which flavanoids and anthocyanin are contained. Our eye muscles can be benefited a lot from this substance. Taking such pills everyday is essential.
The problem of bad elasticity in the blood vessels can also be avoided by intaking some grape seeds extract. If our blood vessels lose their elasticity, we will suffer a lot. These pills can help prompt the circulation of our blood. Take some everyday.
The commonest Vitamin C is still very important, for it is essential for the synthesis of some tissues. Like lutein, it is also an antioxidant substance. Take some Vitamins C pills everyday.
more related article
·Vitamin C and bioflavonoid for healthy eyes
·Attach Importance of Eye Health Maintenance
Firmoo.com is the emerging online optical store selling high quality eyewear, such as prescription eyeglasses (single vision myopic glasses, reading glasses, bifocal and progressive eyeglasses etc.,), prescription sunglasses (with RX tinted lenses), prescription sports goggles. Firmoo guarantees lowest possible price in the market. Firmoo’s return and refund policy makes any purchase risk-free ones.
Article Source:http://www.articlesbase.com/vision-articles/how-to-maintain-the-health-of-our-eyes-1648237.html