Bifocal Lens invented by Benjamin Franklin in year 1784 Invented by : Benjamin Franklin Invented in year : 1784 Bifocals are eyeglasses with two distinct optical powers. The are composed of a lens having one section that corrects for distant vision and another section that corrects for near vision. They are also known as 'Benjamin Franklin Bifocals' or 'Benjamin Franklin Glasses'. Bifocals are most commonly prescribed to people with presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism. Original bifocals were designed with the most convex lenses (for close viewing) in the lower half of the frame and the least convex lenses on the upper. Up until the beginning of the 20th century two separate lenses were cut in half and combined together in the rim of the frame. The mounting of two half lenses into a single frame led to a number of early complications and rendered such spectacles quite fragile. History In 1784, Benjamin Franklin developed bifocal glasses. He was getting old and was having trouble seeing both up-close and at a distance.

Getting tired of switching between two types of glasses, he devised a way to have both types of lenses fit into the frame. The distance lens was placed at the top and the the up-close lens was placed at the bottom. John Isaac Hawkins, the inventor of trifocal lenses, coined the term bifocals in 1824 and credited Dr. Franklin. Development in the invention of Bifocals Towards the end of 19th century Louis de Wecker devised a method to fuse the lenses together. This method was later patented by Dr. John L. Borsch, Jr. in 1908. Just a couple years later, the first single piece bifocal lens appeared. Bifocal lenses evolved rapidly throughout the 20th century. In the 1980s the first bifocal contact lenses appeared. Multifocals were later developed which let's one focus through different prescriptions at different distances through the same lens - hence the name. Bifocals (meaning a lens with two points of focus — usually one for distance and one for near) are the most commonly prescribed multifocal lenses.

Role of Bifocals in the development of human life It is because of the invention of Benjamin Franklin that people with eye problems are able to read comfortably. The invention has laid the foundation for further research which continues to eliminate the limited field of vision in current bifocals. New materials and technologies may provide a method which can selectively adjust the optical power of a lens. Researchers have constructed such a lens using a liquid crystal layer sandwiched between two glass substrates. Other Inventions The 'inventor' of bifocals? The 'inventor' of bifocals? The Politician, Stephen Elmer, 1777 US statesman Benjamin Franklin has long been credited with the invention of bifocal spectacle lenses, but whether this is historically accurate or merely a myth is a matter of debate. Most serious historians now agree that the hard evidence is lacking. Benjamin Franklin, writer, politician, scientist and optician, was a great advocate of air bathing and is known to have favoured sitting naked each morning before an open window.

Presumably he did not curtail this activity while lodging at what is now number 36 Craven Street (a few doors down from the present College of Optometrists' headquarters) between 1757 and 1775. Franklin can still be seen in the street (fully clothed) in this oil painting by royal academician Stephen Elmer, dated 1777. The portrait was acquired by the Museum in 1939. A subsequent copy of the painting is also on display at the US Embassy building in Paris. Franklin is known to have worn temple spectacles after his arrival in England, as must have done other members of his family. In February 1757 he wrote to his wife Deborah Franklin to describe the new furnishings in his Craven Street lodgings: 'Look at the figures on the China Bowl and Coffee Cups, with your spectacles on; they will bear examining'. In this painting, however, he is shown wearing silver folding nose spectacles, a precursor of pince-nez, but the College's interest in this portrait stems not from the eyewear depicted, but from the claim that Franklin was the inventor of the split-bifocal lens.

The idea of a split lens, for use as a trial lens rather than for spectacles, had been suggested by Zahn in 1683 and, again, by Hertel in 1716, but there is no evidence that such lenses served a practical, ophthalmic function until several decades later. Franklin wore spectacles continually after 1776. He admitted in 1784 that without them he could not 'distinguish a letter even of large print'. In 1779, whilst on his diplomatic mission to France which lasted from 1777-1785, Franklin had ordered a pair of spectacles from the English optician, Sykes, who had a business on the Place du Palais-Royale. The fact that Sykes wrote to Franklin explaining that his spectacles had been delayed due to the lenses having broken three times during cutting has been taken as evidence that the ambassador was ordering something out of the ordinary. The price of 18F, which he paid for the spectacles, was certainly higher than was usual at the time.

In a letter of August 1784, written to his friend George Whatley, Franklin declared himself 'happy in the invention of double spectacles, which serving for distant objects as well as near ones, make my eyes as useful to me as ever they were'. It should be noted that he did not describe them as 'my' invention, nor should the wording be taken necessarily to mean that the invention was recent. Whatley replied, referring to the spectacles as 'your invention' and as something he had been discussing with the English optician, Peter Dollond. The Dollonds were, it seems, producing spectacles of this, or a similar, type, as a bespoke service, but were not convinced that the idea had commercial potential. Bifocal spectacles were described in a further letter of Franklin's to Whatley, dated 23 May 1785. In this he again referred to 'my double spectacles' (where 'my' need only signify ownership) and provided a sketch. The letter continued: 'The same convexity of glass, through which a man sees clearest and best at the distance proper for reading, is not the best for greater distances.

I therefore had formerly two pair of spectacles, which I shifted occasionally, as in travelling I sometimes read, and often wanted to regard the prospects. Finding this change troublesome, and not always sufficiently ready, I had the glasses cut and half of each kind associated in the same circle. By this means, as I wear my spectacles constantly, I have only to move my eyes up or down, as I want to see distinctly far or near, the proper glasses being always ready.' A modern replica pair of the type of split bifocal spectacles known to have been worn by Benjamin Franklin in the mid 1780s Some historians, however, have suggested that in this letter to Whatley, Franklin refers to an experiment carried out more than 20 years earlier in London. A letter from the newspaper editor, John Fenno, to his wife dated 8 March 1789, supports this theory. In it Fenno describes a meeting with Franklin in which the elderly statesman had mentioned wearing the spectacles over many years: 'He informed me that he had worn spectacles for 50 years; each eye appeared to be formed of two pieces of glass divided horizontally - he informed me that he had always worn such'.

The Fenno letter also fits in with the fact that Franklin suffered from hyperopia, requiring spectacles for this condition as early as the 1730s. This would have made him likely to have benefited from bifocals by the time he arrived in London in 1757. Before leaving the America the first time Franklin had clearly had an interest in optical developments. He imported vision aids and advertised 'spectacles of several sorts' in the Pennsylvania Gazette. Our knowlege that he was involved in the supply of spectacles in his early adult life may cause us to consider that he may well have had the interest to experiment with bifocals at an earlier date. Yet the only portrait of Franklin in which he is depicted wearing bifocals is one by Charles Willson Peale, dated 1785, when the old man was aged 81 and living once again in Pennsylvania. This does at least suggest that we would be right to say that Franklin introduced bifocals to America. Wider public awareness of the invention only came about in the early 1790s, following Franklin's death.

A genuine pair of split bifocal spectacles, possibly c.1790s though the sliding sides mean we cannot guarantee they are any earlier than 1806 During this period several authors published the Whatley letter, thereby cementing in the public mind the link between bifocals and Franklin. Peale, having painted Franklin wearing bifocals, is known to have made his own pair in 1788 and may have been responsible for introducing the concept to the first US optician, John McAllister, some time after 1799. The idea for bifocal spectacles, attributed by some people to Franklin in both Britain and the US, (though never patented by him or anyone else) soon led to further developments. The use of hinged supplementary visors (to hold reading lenses) was patented in London by John Richardson in 1797. By 1836 Isaac Schnaitman, a German immigrant to Philadelphia, had taken out a patent on one-piece lenses with both distance and reading portions ground on to one piece of glass. Another claimant to the title?

Benjamin West (1738-1820), an American artist, originally from Philadelphia was a natural friend for Franklin in London. He woul;d later become President of the Royal Academy from 1792-1815. West is known to have been an early wearer of 'divided glasses' or bifocals, possibly before 1800, but probably not before Franklin. That has not stopped historians pushing the claim of West or his predecessor at the Royal Academy, Sir Joshua Reynolds, to have 'invented' bifocals in the 1760s. Why anyone should be so determined to attribute their invention to a prominent named individual is perhaps the more baffling question. It does seem likely, however, that these men, especially West, were using split lenses supplied by London opticians for artistic purposes, if not for normal vision, and that this may have prompted Franklin to order some. The Definitive Word...for now Unless further evidence emerges all we can say for certain is that Franklin was one of the first people to wear split bifocals and this act of wearing them caused his name to be associated with the type from an early date.

This no doubt contributed greatly to their popularisation. The evidence implies, however, that when he sought to order lenses of this type the London opticians were already familiar with them. Other members of Franklin's circle of British friends may have worn them even earlier, from the 1760s, but it is at best uncertain (and arguably improbable?) that split bifocal lenses had a famous gentleman inventor. Why not combine your visit to the museum at the College of Optometrists with a visit to our near neighbour, the Benjamin Franklin House , the only surviving Franklin residence in the world? Invention : Bifocals Benjamin Franklin was the first inventor of bifocals in 1784. When was the Bifocals invented? 1784. When the patent was granted on the Bifocals? Addison Smith was granted a patent for bifocals in 1783 and later in 1797 J.R. Richardson was granted patent for the bifocals . Who was the patent granted to on the Bifocals? Addison Smith and J.R. Richardson. What is a Bifocal? Bifocal is a contact lens that is used to view the objects clearly.

There are two focal points available on the lenses one for viewing closer objects and the other for viewing far objects. You can see a visible line on the glasses. The lower line of the glass is used to view closer objects and the above the line you can able to view the distant objects. Depending on your requirement you can select a half moon or circular shape for viewing closer objects. Bifocal glasses are most useful for persons having both far and close sight. Benjamin Franklin suffered from both far and near sight so, in 1784 he invented bifocal glasses by combining two lens to view both close and far view. It will takes time to adjust with bifocal glasses. The frame you wear on your eyes to view the sites must be too tight or too loose you should feel them comfortable. Try to view some object at nearly twenty feet distance with your bifocal glasses while seeing if you see the line on the glasses clearly then contact your optician to adjust them. For viewing closer objects just read a book or something but just keeping it at a distance you read. If you can view them clearly then the glasses are placed in correct position.

Benjamin Franklin-Father of the Bifocal Benjamin Franklin-Father of the Bifocal + Larger Font | - Smaller Font Adapted from the important key article by Dr. Charles Letocha, also the wonderful book by Dr. John Levene and finally the comprehensive paper (yet unpublished) by Stuart Green. In 1990 the year of the bicentennial celebration of Benjamin Franklinâ€™s death (1706-1790) a comprehensive article was published by Dr. Charles Letocha, â€œThe Invention and Early Manufacture of Bifocalsâ€�. It presented Benjamin Franklin as the inventor of bifocals. It is still considered the definitive paper on this topic because no new information has surfaced to the contrary during the past 15 years. This current year 2006 is the tercentenary of Franklinâ€™s birth and therefore we can again recognize Franklin for his major role in the development of bifocal eyeglasses. No one else deserves this esteemed honor: Ben Franklin-Father of the Bifocal. The invention of bifocals had been reviewed in great detail by Dr. John R.

Levene in Chapter 6 of his book Clinical Refraction and Visual Science, Butterworthâ€™s, 1977. Highly regarded as a diplomat and as a scientist, Franklin is generally acknowledged for all his ingenious contributions to many very practical inventions. He had talents and also numerous interests and his natural curiosity led to the search to discover ways to make things work better. One of his greatest innovations was â€œmy double spectaclesâ€� and Franklin has been quite appropriately recognized and universally admired as their inventor. Certainly among the most useful inventions of all time bifocals have serviced billions of people over the past 200 + years. Compound corrective lenses, usually bifocals or trifocals, and with increasing frequency, progressive multifocal length eyeglasses are the modern-day result of the remarkable evolution from Benjamin Franklinâ€™s original simple and practical creation. THE EVIDENCE SUPPORTING FRANKLIN 1). Benjamin Franklin was a hyperope who likely required eyeglasses originally in the 1730s. By the late 1750s he was usually described wearing them and they became an integral part of his face, at least for distance use.

Many paintings and contemporary sketches and satirical cartoons show him represented wearing his eyeglasses. He admitted that he could not â€œdistinguish a letter or even of large print without themâ€�. 2). The Library Company of Philadelphia, founded by Franklin and some of his friends, became Americaâ€™s first lending library. In its print archives there exists a 1764 political cartoon which depicts Franklin wearing an unusual pair of eyeglasses, interpreted by some knowledgeable people as bifocals because the upper portion of each lens appears different from the lower portion. Take a close look and decide for yourself. 3). Von Rohr and several others credit optician Samuel Pierce with making bifocals for Franklin. Pierce described people wearing bifocals in 1775 and he himself may have worn them in the 1760â€™s. Although this is all noted in the Leveneâ€™s chapter no hard evidence is presented. 4). Mr. H.

Sykes, an English optician living in Paris, with a business on the Place du Palais-Royale, wrote to Franklin April 24, 1779 and explained the delay in sending Franklinâ€™s order, complained he was having difficulty making the eyeglasses. â€œI should have sent your spectacles sooner, but in compliance with your favor of the 20th inst., have cut a second pair, in which I have been unfortunate for I broke and spoilt three glasses.â€�Sykes had apparently damaged them while â€œcuttingâ€� them in half. The word â€œcutâ€� is emphasized as opposed to the word â€œgrindâ€�. Even Sykesâ€™ charge for this service (18f a pair) was quite excessive when compared to the normal fee of making simple ordinary glasses. 5).

During his stay in Passy, outside of Paris, Franklin (serving as the American envoy to the Court of Louis XVI) described in a letter dated August 21, 1784 to his close friend and philanthropist George Whatley: â€¦â€¦.â€�I cannot distinguish a letter even of large print; but am happy in the invention of double spectacles, which serving for distant objects as well as near ones, make my eyes as useful to me as ever they were: If all the other defects and infirmities were as easily and cheaply remedied, it would be worth while for friends to live a good deal longerâ€¦..â€� 6). In a letter dated November 15, 1784 Whatley wrote back: â€œI have spoken to Peter Dollond about YOUR invention of double spectacles, and, by all I can garner,â€¦â€¦.â€� 7). Another correspondence with Whatley May 23, 1785 further explains Franklinâ€™s basic position on this matter.

Noted London optician Peter Dollond had stated they were only good for â€œparticular eyesâ€�. Franklinâ€™s reply is certainly very persuasive evidence that he was the inventor: â€¦â€¦â€¦â€¦..â€�By M. Dollondâ€™s saying that MY double spectacles can only serve particular eyes, I doubt he has not been rightly informed of their construction. I imagine it will be found pretty generally true, that the same convexity of glass, through which a man sees clearly at distance proper for reading, is not the best for greater distances. I therefore had formerly two pairs of spectacles, which I shifted occasionally, as in traveling I sometimes read, and often wanted to regards the prospects. Finding the change troublesome, and not always sufficiently ready, I had the glasses cut and half of each kind associated in the same circle, thus (his well-known drawing is in this letter which now resides in the Library of Congress). By this means, as I wear my spectacles constantly, I have only to move my eyes up or down, as I want to see distinctly far or near, the proper glass being always ready.

This I find more particularly convenient since my being in France, the glasses that serve me best at table to see what I eat, not being the best to see the faces of those on the other side of the table who speak to me; and when oneâ€™s ears are not well accustomed to the sounds of a language, a sight of the movements in the features of him that speaks helps to explain, so that I understand French better by the help of my spectacles.â€� 8). Whatleyâ€™s next reply dated July 22, 1785; â€¦â€¦â€¦.â€�The Dollonds are obliged by what you have been at pains to say, and describe of your double spectacles. They fully comprehend it at eh same time say, for such sight as yours are common. That therefore they only make for such as like yours when bespoke.â€� 9). Charles Wilson Peale painted Benjamin Franklin in 1785 and the painting is the only one showing Franklin wearing double spectacles. The bifocals are a prominent feature of this famous artwork. No earlier depiction of anyone else wearing bifocals is known to exist anywhere in the world!

This unique art treasure is at the Pennsylvania Academy of the Fine Arts in Philadelphia. 10). In 1788 Peale made his own bifocals, as noted in his diary for August 25th. These became quite helpful when he painted miniatures. â€œIt would appear that Charles Wilson Peale helped to popularize bifocals in America because he probably taught their method of manufacture to John McAllister, Sr. first American opticianâ€� (the Letocha article). 11). Correspondence from John Fenno, editor of the Gazette of the United States, to his wife March 8, 1789 described a meeting in Philadelphia during the last year of Franklinâ€™s life. The evidence in this letter points strongly to Franklin. It currently is housed at the William C. Clements Library, University of Michigan. â€œHe informed me that he had worn spectacles for 50 years.

He had them on and as they appeared to be differently constructed from any I had seen the circumstance led to some inquiry - each eye appeared to be formed of two pieces of glass divided horizontally â€“ he informed me that he had always worn such â€“ the upper part was to view distant objects, the lower to read with. â€¦.â€� 12). In 1790 Dr. William Rowley published the book A Treatise on One Hundred and Eighteen Principal Diseases soon after Franklin passed away. He quoted the May 23, 1785 letter to Whatleyâ€¦ â€œA species of spectacles has been recommended by the late Dr. Franklinâ€¦â€� Thus he was the first to inform the medical community of Franklinâ€™s invention. He also went on to say that he recommended double spectacles to some of his friends, â€œby whom they are highly approved.â€� 13). In the August 1791 issue of Massachusetts Magazine, the general public first learned of Franklinâ€™s double spectacles.

Lewis Leprelete wrote to the editors quoting the same May 23, 1785 letter from Franklin to Whatley announcing that â€œA species of spectacles has been recommended by the late Dr. Franklinâ€¦..as it is an important object, I have no doubt but you will be pleased to gratify the publick with it,â€¦â€� 14). President Thomas Jefferson communicated with John McAllister Sr. and also with Charles Peale in a fascinating group of letters between 1806 and 1808. referring to the Franklin bifocal on Nov. 12, 1806. This letter is held by the Library of Congress: â€œYou have heretofore furnished me with spectacles, so reduced in size as to give facility to the looking over their top without moving them. This has been a great convenienceâ€¦â€¦â€¦Those who are obliged to use spectacles know what a convenience it would be to have different magnifiers in the same frame. Dr.

Franklin tried this by semicircular glasses joined horizontally, the upper & lower semicircles of different powers, which he told me answered perfectly. I wish to try it and therefore send you a drawing No. 2 agreeably to which, exactly, I will ask another pair of spring frames to be made.â€� Jefferson had been in France during the 1784-9 period, being successor to Franklin as minister. Obviously he observed Franklin wearing his bifocals when they were together. Later in 1807 Jefferson showed his satisfaction with his new bifocals in a letter to Peale March 29th 1807. He noted that he had â€œadopted Dr. Franklinâ€™s plan of half glasses of different focal distances, with great advantageâ€� Jefferson wrote to McAllister on March 16, 1808 that he was â€œextremely satisfied with Dr.

Franklinâ€™s method of joining the spectacles by composing each glass of two half-glasses of different magnifying powers, and those you made for me answer positively except that the frames being circular, the glasses are always turning around and bringing the seam between the two half glasses in the way of the eye. To prevent this the frame should be oval.â€� McAllister had earlier replied to Jefferson, who was by then President of the United, that he had already made such glasses for members of the Peale family and instructed Jefferson how to measure the distance between his pupils and determine the focal length of his current glasses. 15). The well-known French optician-engineer Jean Gabriel Augustin Chevallier discussed the 'Besicles a la Franklin' in the Gazette de Sante (June 11, 1806) which was subsequently reprinted in his Conservateur de la Vue (1810) and later editions of this well known book. 16). Seventeen years after Franklin died, Charles Wilson Peale painted a portrait of himself wearing bifocals. 17).

John Isaac Hawkins, engineer and inventor of the trifocal in 1826, coined the term bifocal in 1824 and he credited Franklin with the invention of the bifocal. ADDITIONAL GENERAL POINTS OF INTEREST 1) The idea of a split lens or lenses of different powers in one frame was originally suggested by J. Zahn back in 1683 and also by CG Hertel in 1716. In both these instances however it was possibly for trial lenses and not for use as eyeglasses. Does anyone know what these lenses definitely were for? 2) Benjamin Franklin began to advertise eyeglasses for sale in his newspaper, the Pennsylvania Gazette, as early as 1738. With moderate hyperopia he would have found eyeglasses to correct farsightedness useful by this time, about age 30. 3) No double spectacles (split-lens bifocals) have ever been found among Franklinâ€™s possessions nor, for that matter, have any of his ordinary eyeglasses been found either.

4) Sir Joshua Reynolds (1723-1792), 1st President of the Royal Academy and an eminent artist, was known to be a myope. His famous self-portrait of 1788 shows him wearing silver turn-pin wig spectacles. He may have worn bifocals made by Dollond. However he was myopic and could merely take his glasses off to do reading and writing and possibly therefore even painting. 5) Benjamin West (1738-1820), 2nd President of the Royal Academy and another eminent artist, wore bifocals perhaps made by Samuel Pierce. But West was a hyperope and likely would not have required them until the early 1790s. West was thirty years younger than Franklin and likely too young to have required them earlier that Franklin. In 1824 Samuel Pierce recorded comments that West had worn bifocals for years. Any artist would have appreciated the usefulness of bifocals, especially as he/she grew older. Pierce commented that he had known â€œseveral painters and other artistsâ€� who had used bifocals when they reached 60 â€“ 70 years of age.

6) Since both Benjamin West and his teacher Sir Joshua Reynolds could have had bifocal spectacles in the mid-1780s it is easy to see why some historians have suggested that either one of them could have originally invented them. But neither West nor Reynolds ever spoke up that they had been the first to conceive of bifocals. Neither of them has been as directly linked with this invention as Franklin has. 7) Franklinâ€™s name has been typically associated with bifocals, not the name of West or Reynolds. This invention was attributed to Franklin during the lifetimes of both West and Reynolds. If either of them was the inventor or if either knew of an inventor other than Franklin, wouldnâ€™t they have said something about it? 8) The â€œLondon opticiansâ€� advertised pretty heavily. If they had invented something as interesting as bifocals, wouldnâ€™t one expect they would have mentioned it in their advertising? 9) Patents were granted to Addison Smith in 1783 and to J.R. Richardson in London in 1797 for what could be called an alternative to bifocals.

Each was comprised of an extra pair of lenses hinged to the main spectacles, the Addison Smith variety came down from above while the Richardson variety rotated in from the sides behind the distance correction, in order to correct for near work. Dutch painter Rienk Jelderhuis is shown in a portrait in 1791 wearing an unusual style of double glasses. He had invented these with the distance prescription fixed in a frame attached to the top of each reading glass. 10) Thus during Franklinâ€™s lifetime and shortly thereafter, imaginative opticians came up with several eyeglasses designs that could be used for both near and distance vision. Franklinâ€™s bifocals however gradually became the dominant form of combined eyeglasses, although there were some problems with them. Opticians had a challenging time grinding the seam edge perfectly flat and keeping the half lenses from falling out of the frames. Lenses also rotated in the round frame also creating a problem. Another great annoyance was the dirt that accumulated in the seam line between the two half lenses, causing a visible dark line at the transition ridge. 11) Here is a bit of trivia about U.S. presidents and glasses. H. R.

Brands in his biography of Andrew Jackson, writing about his first inauguration wrote "Jackson remained standing before the crowd. He wore two pairs of eyeglasses: one currently on his eyes, the other-his reading glasses-thrown on the top of his head" One can assume from this that Ben Franklin's bifocals were still not in common use by 1829. (per Paul A. Rittenhouse) 12) George Elkington (1801-1865) patented two pair together in the same frame with a 45 degree angle induced in the bottom pair. Therefore they were half eyes and also pulpit glasses. 13) Isaac Schnaitman (1795-1875) was a German immigrant to Philadelphia who patented in 1834 a one-piece bifocal which is in fact inverted (upturned). To create this he took a minus tool and ground a small round section at the top of a plus lens. 14) 1861 John Braham patented auxiliary glasses (front hangers or grab-fronts). 15) In the OAICC Newsletter July 1998, N.

64 â€œNow that the College of Optometrists is housed at 42 Craven Street in London it is of particular note that Benjamin Franklin, the Inventor of Bifocals, lived at 36 Craven Street, just a few yards away, from 1757 until 1772. ***This statement is, by itself, significant confirmation because this publication and its greatly admired and highly-respected editor Ronald MacGregor are considered authoritative to me - DAF) ADDITIONAL RESEARCH Two researchers who I admire and respect have also examined the available evidence regarding Franklin. Their conclusions were: Dr. Charles Letocha, York, Pa â€œIt seems most likely that Benjamin Franklin did invent bifocals, most likely when he was in London in the 1760s or early 1770s. As a rule Franklinâ€™s inventions were practical things to solve practical problems. These included the Franklin stove, the lightning rod, a flexible catheter, an odometer, and a long arm to retrieve books from high shelves. The bifocal fits very nicely into this Franklinesque list." Alan McBrayer, Charlotte, NC 1.

The primary sources by Franklin with his description were the genesis of his idea. 2. This invention became known in England in a widely-read book in 1789 and in America in 1790, and nobody stepped forward and claimed prior invention. Even English newspapers and books attribute bifocals to Franklin. 3. The seeming lack of real primary sources that show early use by others (Peale excepted). There are no primary source documents that place bifocals on any faces except Franklin and Peale before 1800. 4. ***The 1804 comments of William Jones, apprentice to Benjamin Martin, employee of George Adams, Jr. and his father's business, and partner in his own business. In A Journal of Natural Philosophy, Chemistry and the Arts, March 1804, Volume VII, page 194, he mentions â€œThe bisected glasses of Dr. Franklinâ€�. Jones spent nearly fifty years in the thick of the optical scene in England and in this statement he attributes the invention to Franklin. Jones worked at "W. & S. Jones", a very large optical manufacturer on Hobron Street.

They had a series of catalogs 1792 - c1810 that listed about every optical instrument available. Jones personally knew Franklin, was a member of the American Philosophical Society, and was very much at the top of the optical scene in Britain 1760 and then for the fifty years thereafter. He is about as "primary source" as it gets. If split bifocals pre-existed Franklin in England somewhere, Jones would have heard about it. His name can be professionally linked with virtually any prominent optician or scientist of his day. CONCLUSIONS Bifocals are attributed to Ben Franklin and he probably came up with the idea by himself. He did not produce them himself but instead had some optician in London or France make them for him. Franklin and his close circle of friends, including West and Reynolds, all probably wore them. Franklinâ€™s discovery of the bifocal is generally felt to have occurred in the early 1760â€™s.

Most hyperopic presbyopes don't go into bifocals until their early 40s so a most realistic earliest date, an educated guess regarding Franklin himself, would be while he was living in London and that started in 1757.It is only from his 1784 letter to George Whatley that we have Franklinâ€™s first statement (with his own drawing) to confirm his involvement. The 1789 Fenno letter is also quite important because it is unique in attempting to possibly date the invention. The bifocal was so typical of Franklinâ€™s many inventions - another practical, elegant, simple solution to a problem he carefully defined. â€œIt just seems so Franklin-esqueâ€�. The important thing to Franklin was always the idea â€“ it would make life simpler for an aging man â€“ â€œanother thing to be freely shared with all old men so that their lives might be made easierâ€� (from a famous quotation by Charles Snyder).

OTHERS WHO ARE ACKNOWLEDGED FOR THEIR KIND SUPPORT Alan McBrayer, authority on American eyeglass makers of the 19th century Adrian Whitcher and Jane Wess from the Science Museum John Alviti from the Franklin Institute Barbara Katus of the Pennsylvania Academy of the Fine Arts Jeffrey Ray of the Atwater Kent Museum Clayton Lewis and John Dann of the Clements Library Charlene Peacock and Jim Green from the Library Company of Philadelphia. Melissa Clemmer and Page Talbott from the Franklin Tercentenary, Ellen Cohn from the Yale University Library My good friend and advisor Dr. Charles (Chuck) Letocha Neil Handley of the British Optical Association Museum Stuart Green Museum of Vision: Exhibitions Museum of Vision Site Viewing Options (CSS support required) Type Size: Timeline of Eyeglasses Leather framed spectacles, c1700 A simple historical timeline of eyeglasses starts with their invention, believed to be between 1268 and 1289 in Italy. The inventor is unknown. The earliest eyeglasses were worn by monks and scholars. They were held in front of the eyes or balanced on the nose.

The invention of the printing press in 1452, the growing rate of literacy and the availability of books, encouraged new designs and the eventual mass production of inexpensive eyeglasses. Find details about eyeglasses in the 18th, 19th and 20th Centuries: 1900s 1700s In the 1700s, eyeglasses were made by hand. The century's most important contributions to eyeglasses were the invention of side or temple pieces that rest over the ear ( first advertised in 1728 ) and bifocals, invented by Benjamin Franklin, in 1784. Common styles in the 1700s included: Martin's Margins . Developed by Benjamin Martin these eyeglasses were characterized by lens inserts commonly carved from cattle horn. Wig spectacles . These were eyeglasses with long temple pieces that extended far beyond the ears. These were popular during this period among men who regularly wore wigs. Bifocals .

Invented by Benjamin Franklin (1706-1790) in 1784, the bifocal was an extremely important invention in the history of eyeglasses. Scissor spectacles . These eyeglasses were commonly used by men who did not wish to wear their eyeglasses. U.S. President George Washington and Napoleon Bonaparte both used scissor spectacles. 1800s Larger scale manufacturing started to become possible by the end of this century and eyeglasses came in fewer styles. A large percentage of people bought cheap ready-made glasses sold by traveling peddlers, jewelers and at general stores. Lorgnette In the 1800s eyeglasses were considered evidence of old age and infirmity. As a result, people preferred to wear spectacles only when they were needed. This was especially true for women. Those who could afford it found hand-held designs such as the lorgnette to avoid having glasses on their faces. Lorgnettes were developed around 1780 from scissor spectacles. Early lorgnette designs consisted of a pair of eyeglasses with a single, long handle.

In 1830, a French manufacturer designed a hinged bridge with a spring, which allowed the eyeglasses to be folded. Lorgnettes became so popular during the mid to late 1800s that manufacturers placed them into all manner of objects including mechanical pencils , fans and even an ear trumpet . 1900s The 1900s saw eyeglasses become an industry of their own, complete with manufacturing and distribution networks. Styles quickly changed in this century as Hollywood and celebrities began to influence fashion and new materials became available, especially plastics. 1900-1920 As the 19th Century came to a close, more and more people wore their eyeglasses everyday. A popular style of inexpensive, everyday spectacles was the pince-nez . French for "pinch nose," the pince-nez was first developed in France circa 1840 and began to be imported to America after the 1850s. Pince-nez have no temples, but are fit snugly on the bridge of the nose. Pince- nez could be uncomfortable to wear and broke often from falling off the nose.

The popularity of pince-nez was helped by political figures such as U.S. Presidents Teddy Roosevelt and Calvin Coolidge who wore them regularly. 1920 to 1950 Although pince-nez were still widely popular in the 1920s, they began to be seen as stuffy and old-fashioned. A Hollywood actor named Harold Lloyd was known for wearing tortoiseshell spectacles with large, round lenses . His photos and Hollywood movies started a fashion craze for temple spectacles. In the 1930s sunglasses became popular for the first time. Although colored lenses were available early in spectacle manufacturing, it was not until 1913 that Sir William Crookes of England created a lens capable of absorbing both ultraviolet and infrared light. Further advances in sunglass design were accomplished in order to meet the needs of military pilots in World War II (1939 - 1945) . As a result, manufacturers began to market sunglasses that were both practical and fashionable. By the 1940s, advances in the manufacture of plastics made a large variety of spectacles available in every color of the rainbow.

Women wore frames characterized by an upsweep on the top rim , a style that was very popular until the end of the 1950s, while men tended to sport gold wire frames. 1950 to Today By the latter half of the 20th century, spectacles were considered part of a person's wardrobe. Similar to clothes, eyeglasses needed to be continually updated or a person could be perceived as old-fashioned. More and more celebrities were influencing spectacle fashion, for example, in the 1970s Jacqueline Kennedy Onassis helped to popularize oversized lenses . Starting in the 1980s technical innovations produced higher quality, plastic lenses. These were lighter and safer to wear. Ben Franklin and the Bifocal | Medgadget Ben Franklin and the Bifocal July 22nd, 2005 Facebook Twitter Google+ LinkedIn When you think of medgadgets, maybe eyeglasses don’t spring to mind — probably because they’ve been around so long, and are so prevalent. But sometimes you realize the importance of something from its absence, as this report from St. Louis University illustrates.

Eyeglasses have been around so long that the most recent major innovations, sunglasses and bifocals, were centuries ago (we’re not counting the passing fad of “contact lenses”). Many people, including this site , breezily summarize the history of eyeglasses, and attribute the bifocal’s origin to Ben Franklin: Glass lenses, for use as magnifiers or for starting fires, date to about 300 BC, but the first eyeglasses to aid or correct vision were almost certainly invented in 1280 in Florence, Italy by the Dominican friar Alessandro della Spina and / or his friend, the physicist Salvino degli Armati. Prescribed for far-sightedness, the glasses had convex lenses and were worn by Armati, who had injured his eyes while performing light refraction experiments and discovered that it was possible to enlarge the appearance of objects by looking through two pieces of convex glass. It was in the early fourteenth century that concave lenses were used to correct near-sightedness. In fact, Pope Leo X was depicted wearing glasses, with concave lenses, in a 1517 painting by Raphael.

Whereas early eyeglasses were made of polished quartz, by the sixteenth century developments in glassmaking made it possible to mass produce them from glass. Bifocals, the combination of both concave and convex lenses for both types of vision correction, a top lens for distant viewing and a lower lens for reading, were developed around 1760 by the American statesman and inventor Benjamin Franklin. Medgadget has profiled a number of celebrity inventors of late, so we naturally gravitated toward Franklin. At first glance, his letters ( excerpted here ) seem to bear out his role in this invention: While working as US ambassador to France in 1779, Franklin had ordered a pair of spectacles from the English optician, Sykes, who had a business on the Place du Palais-Royale. The fact that Sykes wrote to Franklin explaining that his spectacles had been delayed due to the lenses having broken three times during cutting has been taken as evidence that the ambassador was ordering something out of the ordinary. The price of 18F, which he paid for the spectacles, was certainly higher than was usual at the time.

In a letter of August 1784, written to his friend George Whatley, Franklin declared himself ‘happy in the invention of double spectacles, which serving for distant objects as well as near ones, make my eyes as useful to me as ever they were’. But we were dismayed to learn Franklin’s legend may not be all it’s cracked up to be: The Dollonds were, it seems, producing spectacles of this, or a similar, type, as a bespoke service, but were not convinced that the idea had commercial potential. Bifocal spectacles were described in Franklin’s in a further letter to Whatley, dated 23 May 1785. In this he again referred to ‘my double spectacles’ and provided a sketch. The letter continued: ‘The same convexity of glass, through which a man sees clearest and best at the distance proper for reading, is not the best for greater distances. I therefore had formerly two pair of spectacles, which I shifted occasionally, as in travelling I sometimes read, and often wanted to regard the prospects. Finding this change troublesome, and not always sufficiently ready, I had the glasses cut and half of each kind associated in the same circle.

By this means, as I wear my spectacles constantly, I have only to move my eyes up or down, as I want to see distinctly far or near, the proper glasses being always ready.’ Some historians, however, have suggested that in this letter to Whatley, Franklin refers to an experiment carried out more than 20 years earlier in London. A letter from the newspaper editor, John Fenno, to his wife dated 8 March 1789, supports this theory. In it Fenno describes a meeting with Franklin in which the elderly statesman had mentioned wearing the spectacles over many years: ‘He informed me that he had worn spectacles for 50 years; Split bifocal spectacles c.1780s-1790seach eye appeared to be formed of two pieces of glass divided horizontally – he informed me that he had always worn such’. The Fenno letter also fits in with the fact that Franklin suffered from hyperopia, requiring spectacles for this condition as early as the 1730s. This would have made him likely to have benefited from bifocals by the time he arrived in London in 1757.

Before leaving the US, Franklin clearly had an interest in optical developments. He imported vision aids and advertised ‘spectacles of several sorts’ in the Pennsylvania Gazette. This may well have led him to experiment with bifocals at an earlier date. Yet the only portrait of Franklin in which he is depicted wearing bifocals is one by Charles Willson Peale, dated 1785, and public awareness of the invention only came about in the early 1790s, following Franklin’s death. Oh well, at least Franklin has some other accomplishments to fall back on. It’s too bad that being the first to popularize a medical device isn’t the same as inventing it — if we could find a way to do that, we’d be very healthy, wealthy, and wise . That’s all for this week. Take care, enjoy the weekend, and tune in for more on Monday! Nicholas Genes Nicholas Genes, MD, PhD, has been with Medgadget since almost the beginning. He's now Assistant Professor of Emergency Medicine at Mount Sinai, where in addition to patient care and teaching responsibilities, he studies EHR usability and physician uses of social media. Dr.

Genes serves on the editorial boards of Emergency Physicians Monthly and Emergency Medicine Practice. More about Nick: Related Posts Bifocal Lenses | Multifocal | Progressive Lenses | Eyeglass World Multifocal Lenses at Eyeglass World Bifocal Eyeglasses Often those who require prescription glasses need a varying strength of lens depending on distance. Lenses that assist in distance vision may not allow the same person to focus clearly when reading up close. In 1784, Benjamin Franklin was tired of having to change glasses when he needed to look at something up close, and as a result he invented a single pair of spectacles that contained two lenses of varying strength for each eye. Find what's right for you We carry thousands of frames for you to choose from, and we offer 2 pairs for just $138* * and 2 pair specials ** on our entire designer collection everyday! If this sounds familiar, bifocal or other multifocal lenses may be the right choice for you. Call to schedule an eye exam * at Eyeglass World today and get your frames the same day+ with most prescriptions!

Eyeglass World also offers progressive lenses ** which start with the wearer’s distance vision prescription strength at the top of the lens and get stronger towards the bottom. This configuration accommodates reading and other up-close vision tasks that require additional magnification. In addition to the traditional bifocal, multifocal, and progressive eyeglasses at Eyeglass World, we also offer bifocal, multifocal and progressive lens sunglasses **, safety eyewear and contact lenses . **Offer includes select frames and single vision uncoated plastic lenses on both pairs, for the same person. 2 for $158 offer includes select frames and no-line bifocal plastic lenses on both pairs, for the same person. 2 for $138 offer includes select frames and lined bifocal plastic lenses on both pairs, for the same person. Sunglasses can be used with offer if lenses are prescription or upgraded (i.e. Polarized, Drivewear®, etc.). Frame value for free pair still applies at $199.95, even if choosing sunglasses as the free pair. Cannot be combined with any other discount, coupon or insurance plan.

Related Links The History of Glasses - Origins of Eyeglasses Home » Glasses History » History of Glasses Origins and History of Eyeglasses The earliest technology of magnification of images dates back to around 1000 A.D. The first visual aid instruments were reading stones. Those who had invented them observed that a convex shaped glass could magnify the image of a small object. These reading stones were developed to help monks in reading and writing. The monks with presbyopia used reading stones that were placed on the reading material as magnifying glasses. In the 9th century Abbas Ibn Firnas developed a way to produce very clear glass and he is said to be the first to use corrective lenses. These glasses could be shaped and polished into round rocks. The Venetians started to make reading stones out of glass that were placed on the reading material. They later learned to produce them with glass lenses that could be held in front of the eye instead of being onto the text. The first spectacles with its frame and sidebars were probably made in 1268 in Pisa, Italy, but it was not known who invented them. The paintings by Tomasso da Modena in 1352 represent the earliest artistic representation of eyeglasses.

His paintings showed monks reading and copying manuscripts, one using magnifying glass while another had glasses that were perched on his nose. By the 1400s, Florence, Italy became a leader in sale, production and innovation of high quality eyeglasses. It has already been documented that vision declined after the age of 30 and the concept of five-years glasses were made in Florence. Prescriptions were changed every five years as the glasses user aged . Later, eyeglasses were being exported from Italy to other parts of Europe. They could be found in different styles, compositions, and cost and they were most certainly affordable and considered a necessity by every level of society. In the 17th century, Germany became a major player in the history of eyeglasses as it started producing some of the finest looking frames for eyeglasses, while Italy continued to produce the best quality lens. Over time, the construction of spectacle frames also evolved. Early eyepieces were designed to be held in place either by hand or by exerting pressure on the nose (pince-nez).

The earliest spectacles were made from quartz lenses which were designed to be held in place either by hand or by placing on the nose ( pince-nez) which of course was a problem, since noses have different shapes and sides. The modern style of glasses was developed in 1730, when London optician Edward Scarlett devised rigid side pieces that rest atop the ears. This kind of eyeglasses is still in use today. The American scientist Benjamin Franklin, who suffered from both myopia and presbyopia, grew weary of having to switch between distances and reading glasses and developed the bifocal lens in 1784. The lorgnette, a pair of glasses with a handle, was developed in the 18th century. In the 18th century the monocle was introduced and was very popular in the 19th century particularly in Germany and Russia. The British astronomer George Airy developed the first lenses for correcting astigmatism in 1825. By the 20th century, both in America and Europe eye glasses were produced to be functional, comfortable, and stylish. Today, we continue to discover newer, lightweight material for lenses and produce both framed and frameless eyeglasses.

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Question: Who developed bifocal spectacles in 1784?
Answer: Benjamin Franklin