Glasses: A Brief History of Vision Correction

[Music] according to the vision council of america nearly three-quarters of american adults use some sort of vision correction about 61 wear glasses and another 11 were contacts either alone or with glasses according to the website statistia the global eyeglasses market was valued at more than 131 billion dollars in 2018. but the quest for perfect eyesight has a long history and it required many visionary advancements before we could come to the range of products that today help so many of us to keep the world in focus the history of vision correction deserves to be remembered there is an interesting conundrum about vision as science writer brian palmer noted in the washington post in 2013 among wild animals while different species have varying vision depending upon their needs very few seem to have vision problems that is animals by and large do not need glasses the reasoning seems rather simple animals with bad eyesight either will have difficulty finding or catching food or are more likely to be caught as food in the simplest terms of evolution animals with impaired eyesight relative to the needs of their species are less likely to reproduce and that leaves a perplexing question why are there a notable number of humans with poor eyesight shouldn't that trade have evolved away in pre-history during the estimated 90 percent of human existence spent as wandering bands of hunters and gatherers prior to the neolithic revolution where we started to settle down into agricultural communities there are several possible answers first eyesight tends to grade with time and eye impairments become more common as people age animals and humans in the wild might simply not have generally lived long enough to develop vision problems secondly our modern vision issues might be affected by our changed environment we spend more time indoors do more work close up like reading there's some evidence that things like close-up work in less light causes eye muscles to contract over time affecting the shape of the eye causing vision problems like myopia this is partially described in some surprising research that was noted in a june 2017 issue of psychology today children who live in societies where the children spend more time outside have lower incidence of myopia or nearsightedness than children who live in societies where the children spend more time inside other research of the inuit people found that inuit people who continue to live a traditional lifestyle had fewer vision problems than inuit people who had moved to a modern lifestyle finally we've possibly evolved differently as we moved into modern lifestyles modern dog breeds for example show more vision diversity and less potential for vision impairment than wild dogs dog breeding is done for a number of traits but things like color shape and for many breeds there's no longer selection for things like the ability to hunt we have deliberately bred away from the need for some dog breeds to have perfect eyesight perhaps humans having settled down and depending less upon hunting and gathering have selected for different traits allowing eye impairments to relatively prosper this could even be more pronounced if we slowly develop technologies like eyeglasses that make natural visual acuity less important to success and survival and that evolution might be reinforced by changes in selection patterns several pieces of research suggest that people who wear glasses are perceived as being more intelligent and therefore might be more attractive mates our species might literally be selecting for poor eyesight all these ideas are controversial in some ways but they do raise the question when in human history did eye problems become an issue and how have we responded to the issue over time treatments and diagnosis of eye ailments are included in some of the oldest surviving written materials the 18th century bc code of hammurabi representing the code of law of ancient mesopotamia includes a provision that for a successful operation which saves the eye of the patient the fee be ten shekels of silver in the case of a gentleman but only five shekels and two shekels in the case of a poor man and own slave respectively this is the first known written evidence of a discipline devoted to eye health one of the oldest preserved medical documents is the so-called evers papyrus likely written around 1500 bc the 110-page papyrus scroll seems largely to have been copied from earlier texts the egyptian medical papyrus devotes an entire section to diseases of the eye identifying numerous conditions and treatments although the work is likely a work of priests rather than physicians and includes treatments such as incantations and what one history of ophthalmology calls bowel applications and all the other manifestations of superstitious ignorance the surmita an ancient sanskrit text on medicine and surgery dating to sometime in the first millennium bc describes 76 optical conditions and includes a description of couching as a treatment for cataracts the technique which involves using a sharp instrument to push the cloudy lens to the bottom of the eye was widely practiced until the development of modern cataract surgery in the 19th century greek physicians described the anatomy of the eye their descriptions improved over time but still included errors the 4th century bc greek mathematician euclid for example used geometry to describe the cone of an area in which an eye can see but also postulated that sight was the result of rays that emanate from the eye given this early interest in conditions of the eye you might think that the use of corrective lenses also has an ancient origin the making and blowing of glass goes back as far as 3500 bc ancient greeks had at least a basic understanding of refraction some suspect that's a so-called nimrod lens a 3000 year old 1.5 inch diameter crystal unearthed in an archaeological dig of an ancient assyrian palace may have been used to start fires making it the earliest known example of an optical device although others suspect it is merely a piece of decorative inlay the greek playwright aristophanes notes the use of a transparent stone at the druggus with which you may kindle fire in his 424 bc play the clouds in 212 bc the mathematician archimedes of syracuse might have used a large refractive lens essentially a giant magnifying glass to set fire to a roman fleet that was besieging the city the first century ad roman naturalist pliny the elder described using refraction from a glass globe filled with water to cauterize wounds in his contemporary seneca the younger noted that using the same globe you could read letters no matter how small or dim although only fragments survive the second century a.d work optics by the greek mathematician ptolemy demonstrates an understanding of reflection refraction and color so you might think with this interest in the anatomy of the eye and an understanding of glass and optics that the greeks and romans would have come up with the idea of creating lenses and putting them in frames in order to correct vision problems in fact the word lens itself is based on the latin word lentil which is a type of legume which like many lenses is convex on both sides but in fact the greeks and romans did not invent glasses and we know that because there are many greek and roman works where people note that their eyesight grows worse with age and lament that no one had found a solution to the problem in fact the first description of a true lens for magnifying vision appears to be in the 1080 book of optics written by arab scholar ibn al-azad his convex lens used to magnify an image is the first clear description of a magnifying glass sometime thereafter polished hemispherical pieces of crystal or glass called reading stones used to magnify text came into use in europe similar objects are still sold today ibanella since work was translated into latin in the 12th century and scholars such as robert grosstest and roger bacon authored works on optics that seem to fully understand the use of lenses to make a small object placed at a distance to appear as large as we wish it's not clear when exactly the first spectacles fixing lenses into a frame to be worn to improve vision were created but a sermon delivered by a dominican friar in the italian city of pisa in 1306 wrote it is not yet 20 years since there was found the art of making eyeglasses which make for good vision guild regulations for the making of lenses were recorded in venice by 1301 and by the mid-14th century eyeglasses most commonly used to address hyperopia or presbyopia both conditions that affect the ability to see objects like text up close were both mentioned commonly in writings and depicted in art however their use was still rare largely among clergy as a november 2019 edition of bbc news notes glasses were used for reading and only very few people could read the invention the printing press in 1440 created a larger audience in the literacy rate in europe more than doubled in the 200 years following gutenberg's invention more readers meant more demand for glasses and the first specialist spectacle shop opened in strasbourg in 1466. glasses to that point used convex lenses to address hyperopia or presbyopia but those did not address myopia nearsightedness or the inability to clearly see distant objects the first known use of concave lenses to address nearsightedness were created for pope leo the 10th in the 16th century the extremely nearsighted pope used the spectacles for hunting spectacles through the 17th century had limited means to affix them to the face some were tied by ribbons others pinched to the nose held on by friction very often they would simply be held in place by hand in 1727 english optician and instrument maker edward scarlett first invented an eyeglass frame with ear hooks as they're commonly used today glasses that included two distinct optical powers came about in the 1760s the invention is generally credited to benjamin franklin who suffered from both myopia and presbyopia although there are some claims that the idea may have predated franklin the term bifocals was not actually coined until 1827 when prolific english inventor john isaac hawkins patented trifocals which have three optical powers which correct for distance intermediate and near vision in 1825 english mathematician sir george biddle airy created lenses to address another common eye ailment astigmatism the result of irregular curvature of the cornea that can cause blurred vision at any distance english polymath sir john herschel first suggested the possibility of correcting vision with lenses directly over the eye in 1845 but a lens was not practically created and fitted until 1888 by german ophthalmologist adolf ficke fix was considered the first practical contact lens but the heavy blown glass lens covered the entire sclera or front of the eye could only be comfortably warm for a couple of hours in 1948 kevin m tui patented a lens made of acrylic glass that only covered the cornea along cocktail lenses that could be comfortably worn up to 16 hours a day these became the first contact lenses with mass appeal and lyndon johnson became the first president to be photographed in public wearing contact lenses in 1964. the eczema laser which works by emitting light pulses in the ultraviolet spectral range was invented at the lebanese physical institute in moscow in 1970. in 1989 iranian-born ophthalmologist gordon a payment patented a process to use an exmer laser to reshape the cornea to correct hyperopia myopia and astigmatism since it was approved by the fda in 1999 the procedure called lasik for laser-assisted in-situ keratomiliosis has been performed on more than 11 million americans the common method for determining visual acuity owes itself to dutch ophthalmologist herman snellen who in 1862 created the snellen chart the chart shows characters on a 5x5 grid and while he was not the first to create such a chart his quickly became the international standard still widely used today the chart allows a measure of standard vision measured as the ability to correctly read a line of optotype characters when they quote subtended five minutes of arc and were separated by one minute of arc the standard distance to identify the characters is six meters or in america 20 feet normal vision is thus described as 2020 in the united states and 6 6 almost everywhere else to create an eyeglass prescription an optometrist must measure the degree of your refractive error this is done with the device familiar to anyone who has had an eye exam the 4-opter the device contains different lenses used for refraction of the eye during site testing in addition to measuring refractive error can also help to determine characteristics of the patient's binocularity devices of similar purpose existed at least as early as the 18th century but most in use today are based on a 1909 patent by henry desang various improvements were made on the device until the ultramatic rx master was created by american optical in 1967 and 53 years later that is still the prototype for most all four opters in use today some serious diseases of the eye like glaucoma which can be diagnosed using a device invented in 1950 by hans goldman called a tanometer can be successfully treated if they are identified early but an article in a 2010 edition of the new york times entitled what we're not looking after our eyes found that in a survey some 86 of americans who had diagnosed eye diseases were still not getting regular eye exams the survey which was conducted on behalf of the not-for-profit vision and healthcare organization called lighthouse guild was particularly concerning because of the aging of the american population which put some 61 million americans at risk of severe vision loss and it's not just the lost productivity and quality of life that comes with vision loss there's real health impacts as mark ackerman of the lighthouse guild notes some 16 percent of broken hips in america come as a result of accidents caused by vision loss regular eye exams can also identify eye and vision problems in children before it starts to impact their ability to learn in school if the 3 000 year history of studying human eye diseases teaches us anything it's that if you hope to see the future or even what's right in front of your face then you need to take care of your eyes i hope you enjoyed this episode of the history guy short snippets of forgotten history between 10 and 15 minutes long and if you did enjoy please go ahead and click that thumbs up button if you have any questions or comments or suggestions for future episodes please write those in the comment section i will be happy to personally respond be sure to follow the history guy on facebook instagram twitter and check out our merchandise on teespring.com and if you'd like more episodes 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Channel: The History Guy: History Deserves to Be Remembered

Views: 191,986

Keywords: history, the history guy, history guy, glasses, ophthalmology, contact lenses, eyeglasses

Id: cGtpr8N8Xbc

Length: 15min 6sec (906 seconds)

Published: Wed Oct 07 2020