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Low vision devices include eyeglasses, but there are many more low vision products available today that can assist patients in living with macular degeneration symptoms. While laser surgery can be used to treat the "wet" variety of age-related
or AMD, there is no known cure for the "dry" form of this leading cause of blindness. However, low vision devices can help such a victim in making the most of what eyesight remains.
Age related macular degeneration (AMD) affects the central part of the retina, and therefore one's ability to determine fine details such as print, faces, and images. Essentially, one develops a "hole" in one's vision; if the subject is looking at an object that appears smaller than this "hole," the object cannot be seen clearly. Therefore, the purpose of low vision devices is to increase the apparent size of these objects.
Because we use our eyes in different ways in different situations, there is no one solution for addressing macular degeneration symptoms. One patient may require several different low vision products. Bifocal reading glasses are one of the best known and most common low vision devices, but may not be appropriate for all macular degeneration symptoms.
for low vision, also known as bioptic telescopes, are low vision devices that actually consist of miniature telescopes mounted atop a pair of regular glasses. Such low vision devices can be adjusted for a wide range of activities that require both distance and near vision. While
for low vision work in the same way (you tilt your head forward slightly), they differ from bifocal reading glasses in that the telescopic lens is not integrated into the primary lens itself.
Other low vision products for age related macular degeneration include such products as the portable digital magnifier, which resembles "virtual reality" goggles and is used in conjunction with a special pair of glasses. One of the most interesting low vision products on the market today consists of a miniature TV camera that actually rests on the surface of whatever the patient is reading, magnifies it, and sends that image electronically, projecting an image on the inner surfaces of eyeglass lenses! Such a system allows the patient's head to remain in an upright position; no longer is it necessary to tilt one's head.
Of course, such high-tech vision aids are quite expensive at the present. However, if the history of other technologies such as the PC and the DVD is any indicator, the cost of such low vision devices should come down substantially over the next few years.
Do you already need to use spectacles for activities such as reading? At some point in life, reading newspapers and books becomes difficult for some people. While reading glasses may be an option for some, they may not quite work for you in case you already wear glasses for distance vision. It could be taxing, for example, if you had to swap your glasses all the time. The perfect answer to this common problem is simple and effective—bifocals.
Bifocals were invented by the American statesman Benjamin Franklin. Franklin, apparently had two pairs of glasses, and juggling them all the time was particularly inconvenient for someone as busy as him. He came up with a simple solution that was to change the world of optical accessories forever—he just cut the two lenses in half and fitted them one above the other. He combined his two lenses to make a single bifocal lens that would serve the needs of close- as well as distance-vision. This revolutionary idea has seen many mutations, but has survived as a simple and efficient concept that has been indispensable to the optician.
Bifocal lenses are basically a lens with two different specifications for the top and bottom halves. Some of them have a distinct line separating the two. They are called ‘Franklin lenses' or ‘Executive lenses'. Nowadays, however, models are available which do show the distinctive line and are called progressive lenses.
The lower part of the lens is for reading purposes, while the upper half is for visibility at a distance. This is because most people look down while reading and up while looking into the distance.
Four Designs
There are basically four distinctive designs for bifocal lenses, four different ways of embedding the reading lens in the other lens. One way is the Franklin lens, as discussed above. Some other glasses have a round part on the lower side of the lens. Others have a slanted ‘D' shape, or half-moon, while some even go for the ‘ribbon' segment which is a rectangular position along the lower half of the lens.
All said and done, you may go in for any kind of bifocals you are comfortable with. But all of them work on the same basic principle—the lower part for reading and the upper part for seeing—and the various models only provide minor differences in visual definition and ease. Bifocals may be a bit uncomfortable to start with, but as you get used to them and know how to look through each lens, you will be able to fully appreciate the benefits of the innovation that is the bifocal.
Bifocals are the best way to get rid of two sets of glasses. But it doesn't mean you have to throw away your old glasses. Just go to an optician with your lenses and tell him to cut them in half so you can make yourself your very own pair of Franklins.