Bifocals are not a new gift of science of recent times. It was first designed by Benjamin Franklin in order to do away with the continuous adjusting of glasses to align his vision with the shift of near and faraway objects. He designed a glass that allowed him to see the distant objects as clearly as he saw the nearer ones. Benjamin Franklin did this by simply cutting two pairs of different prescription spectacles in half and using half of each lens for each eye. Technology has advanced since then, but the basic way of making it is still the same.
The bifocals which were designed in earlier times had the concept, that generally people look downwards when reading or looking at something close, but looks up when looking at distant objects; this is why the bottom half of the lens was usually designed for close vision. Later versions of the bifocals had the lens cemented onto each other; as for today most bifocals are made by molding one reading lens to the other distant viewing one. The bifocals have many different designs, there are generally varied in their shapes and sizes. There are trifocals too.
Most people opt for bifocals for the vision problem, which is commonly known as presbyopia – the incapability of the eye to focus on objects at different distances. Presbyopia should not be mistaken for long-sightedness, although it is much misunderstood as such. Each year, almost 4 million Americans develop presbyopia, more commonly around their middle age, anytime in between thirty to fifty years of age. If you are a diabetic then you surely have a double chance of getting the handicap of presbyopia.
The first sign is the inabilities to focus your vision on something close, like reading newspaper, books etc. Presbyopia very slowly corrodes the falling years of old age of the patient, to get well you need the medication for almost two years. There is no way to stop it, although it has never been reported to cause a total and permanent blindness.
Bifocals are good for you as you can have your vision cleared, that is, when you use the prescribed lens. The first time users will face a problem when you start to use it; but as the day passes it will get well. It is also possible that things appear closer than they really are when you look through the lower part. The key is to use it and keep using it; the eye like various problems in our life has its own way of setting it right.
Generally the computer users and readers are much helped by the bifocals, as they are constantly changing their focus from one point to another. Some people complain of a ‘headache' after using the bifocals, the headache or the ‘tired eye' is just a scenario that you are facing as a new user. You may have to hold it farther away than natural. It is however recommended that after reading through your bifocal lenses you try to focus on something farther away, this will be a good exercise for your eyes and will help you in a long-term process.
Bifocal Safety Reading Glasses
If you are in your forties or beyond, you are bound to face complications in reading books or newspapers over time, more so if you have been wearing specs all your life. Especially, because if you have had a pair of glasses to see farsighted objects all your life then it becomes difficult to have another pair to see the close objects and to juggle both the pairs. Bifocal reading glasses have been the best solution to this problem.
Bifocals have been the brainchild of the great American Statesman, Benjamin Franklin. His idea caused a revolution in the history of spectacles. According to the story, Benjamin Franklin possessed two separate pair of glasses. One for farsightedness, that is to see distant objects and things and the other for reading.
Since he was a busy person he soon got tired of wearing the different pair of glasses as per requirements. And hence he came up with the revolutionary idea of cutting the two glasses into half and then joining the half to produce a combination of the two glasses that could be worn as one. Hence one single frame had one single lens. This was the Bifocals.
Made of two parts, the bifocal lenses were divided into two parts by a distinct border line-the upper part for distant objects and the lower part for reading. This way of division had a purpose behind it. And that is people generally read by holding their books down while we look up at a distance to see distant objects. These lenses are used even these days and are named after Franklin, called ‘'Franklin Lenses ‘' or ‘'Executive lenses'' (E lenses).These days bifocals come in special ‘'progressive lenses'' where the border line is made invisible.
The significant thing to note about these bifocal lenses is that they can be used for reading. In such cases the upper part of the lens does not have any power. There are four types of bifocal lenses where the reading lens comes within the full lens. And these four types of lenses are:-
• One with the round part at the lower side of the lens.
• Two in a semi circle shape or that of a half moon or slanted D shape.
• A ‘'ribbon segment''which is a small rectangular part in the lower half.
• The Franklin lenses.
Bifocals are indeed one of the most useful things and the best thing about them is that they get better with practice. On using regularly, you get used to using the upper part of the lens for looking at far objects and lower part for reading and then after a few months you will be instinctive in your use of it. Whatever type of reading glass you use, just remember that they work on the same principle of lower half of lens being used for reading purpose and upper half of lens used for looking at distant objects.
The best thing about bifocal reading glasses is that they help in getting rid of two pairs of glasses for two kinds of visual problems. You can always take your old pair of glasses to the optician and get him to cut the lenses into half in order to make you, your very own pair of Franklin lenses.
Suzanne Hughes has sinced written about articles on various topics from Eye Care, Eyewear and Woman Menopause. Suzanne Hughes is an eyewear style consultant specializing in . For more information about eyeglasses, vision, o. Suzanne Hughes's top article generates over 33100 views. to your Favourites.
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