Glass eye from Lauscha
The development of the artificial eye made of Lauscha glass around 1830 is the result of many years of searching and research. The manufacture of artificial eyes for humans can be traced back to the 16th century. The oldest information about this comes from the French royal surgeon Ambroise Paré (1510–1590), who differentiates between two types of artificial eyes:
- The ecblepharon (presenting eye) consisted of a leather-covered steel spring reaching around the head, the end of which was at the back of the head, while the other widened towards the front to form a plate and covered the empty eye socket. An eye with eyelashes and lids had been painted on this surface, also covered with leather.
- The hipoblepharon (inlay eye), which - pushed under the lids - looked more realistic.
At first, silver or copper shells, comparable to half a nutshell, represented the basic body of the artificial eyes. The iris , pupil and veins were painted with enamel paints. Metal intolerance, the weight of these bowls, strong irritation from sharp edges, rapid decomposition of the coatings and less good possibilities for imitation led to the development of bowls made of glass (Jessen, Wittenberg 1601).
Venice as the cradle of the glass eye
As early as 1623, the Venetian surgeon Hieronymus Fabricius mentions glass eyes as "well known". This art, initially only practiced in Venice , then spread to Central Europe in the 17th and 18th centuries. Worm (Lyon 1655) describes glass eyes, the visible side of which is brightly painted with burned-in colors. In order to get an even inner surface, the back was covered with lead . In 1749, in the first monograph on the artificial eye by Phil. Adam Haug, artificial eyes were described as “beautiful and deceptive” (Dissertatio de oculo artificiali praes. BD Mauchard, Tübingen 1749). While Paré's eyes were symmetrical, nasal and temporal the same length, Haug recommended widening on the temples. From around the middle of the 18th century, Paris took the lead in the field of glass eye production as a cultural and art metropolis. Famous French eye artists such as Hazard, Hazard-Mirault, Desjardin's father and son, Boisseneau and Noel made artificial eye assortments in the years that followed, which they made available to ophthalmologists for selection and fitting. In addition to the appearance, attempts were made to remove the discomfort that came with carrying the bowl. While older specimens were made in an oval, symmetrical shape, Hazard-Mirault's replicas show larger, more anatomical shapes. The use of these cup eyes was very limited, as they are only suitable for a smaller eyeball. If this was completely absent, the lost volume could not be compensated for. Well-off patients traveled to Paris to have artificial eyes made and personally adjusted by the producer. Boisseneau was the first to hold travel conference days in major cities in France. Although the price of the product, as well as the short wearing time of the artificial eye of only four to five months due to the high lead content of the glass, made it a luxury item, the success was great. For economic and certainly also political considerations, German ophthalmologists thought about “their own, a German” possibility of producing such glass eyes.
Ludwig Müller-Uri
From the middle of the 18th century, glass eyes for toy animals, dolls made of fur, fabric or wax were already being made in Lauscha, Thuringia . The eyes, whose irides consisted of a black point or of a colored, mostly brown circle, in the center of which a black circle was melted as a pupil - "there was no trace of drawing in the iris" - were in large quantities in the nearby Sonneberg the toy manufacturing needs. The Würzburg medic Prof. Heinrich Adelmann (1807–1884) became aware of particularly well-made doll and animal eyes in 1832, perhaps through his children's toys. He contacted and enthused the talented glassblower "that same year": Ludwig Müller-Uri . According to contemporary accounts, he went “full of energy to work”.
Ludwig Müller-Uri was a Thuringian glassmaker , artificial eye blower and pioneer of German eye prosthetics . He is considered to be the founder of modern ocular studies .
New production method in Lauscha
Müller-Uri had French cup-eye patterns from Adelmann, but no documentation on how they were made. By experimenting with materials and various manual methods, he developed a completely new type of glass eyes. While in France as a base glass lead glass was used Müller-Uri took the melted in the Lauscha glassworks called Beinglas . The white color of this milk glass was achieved by adding to the normal glass raw materials sand, soda and potash from ground (house) animal bones ( bone ash ). Regarding the iris color, Müller-Uri believed that the colors of the French products were painted with enamel paints, which later turned out to be incorrect. After many attempts he found "a usable mixture of enamel colors" and thus developed "his own way of painting enamel colors".
The production of a Müller-Uri eye went something like this: “A section of a glass tube was melted off with two handles, one of them was removed and the rest was blown into a ball. At the front, exactly in the middle, a drop of colored glass was placed as a base glass and everything was put aside for the time being. Now Müller-Uri ... had made the end of a crystal glass stick glow and pushed it wide. In the middle of the resulting plate-shaped surface, he inserted the pupil made of black glass. Around this he created the most diverse nuances of the iris with his enamel colors - a kind of reverse glass painting . This stamp, painted several times in the appropriate layers, was then melted together with the glass ball already provided with the substrate. The base sphere, now again intended for use, made it possible to melt the unneeded crystal glass and fuse it together. ”The next difficulty Müller-Uri had to overcome was to separate the eye cup from the spherical, freely formed glass body. First he had his father-in-law, the glass cutter Karl Greiner-Vetterle, grind out the required segments, which undoubtedly produced sharp edges. The shell had to be reheated to smooth the edge. Due to the hard and brittle leg glass, many eye cups shattered, which at times demotivated Müller-Uri. Only a thermal process could prevent it from shattering. Now Müller-Uri blew a hole in the side of his hot glass body and thermally separated the bowl with the help of a glass rod in the flame, so that the edge could be melted smoothly “without a mistake”.
Lauscha as a competition location to Paris
Müller-Uri achieved its first successes in 1835. A few years later, his products achieved the quality of the Parisian eyes and in the following years surpassed them in terms of beauty in color. His glass eyes were awarded the Great Medal of Merit for Art and Science at the trade and industrial exhibitions in 1844 (Berlin) and 1855 (Munich). Müller-Uri's creations were created by his contemporary, the ophthalmologist Dr. Ritterich from Leipzig, in his 1852 book about the artificial eye equated at least with those of the Parisian artists and "even preferred in several respects". He expressly praises the natural and lively colors, a covered iris - this was translucent in many Parisian eyes - and the fine, filigree grain of the iris structure. Ritterich described the design of the anterior chamber in terms of space and depth as particularly successful. Ritterich thinks that eyes from Venice are “only passable for wax figures”. According to their own statements, the French manufacturers also used smelting works from Venice for their eyes . With regard to the surface quality of his artificial eyes, Müller-Uri was still dissatisfied. Due to the tear fluid and generally known secretions, the artificial eyes became rough after wearing them for a while. In 1849, at the invitation of a business partner, Müller-Uri went to Paris in search of new materials. There he discovered that the French glass was unusable after weeks due to its high lead content. He resisted the poaching attempts of the Parisian ocularists and returned home. Had he his artificial irises been painted with enamel colors, he tried the iris to make all glass. To do this, he made self-rolled colored glass sticks in the most varied of variations, which he melted onto the basic glass body in place of his enamel colors. The decisive factor for him was to achieve a “natural” mixture and the right arrangement of the individual glass strips. The French plucked their irises with coarse glass threads onto the crystal glass temple, but after applying the pupil they did not melt it onto the artificial dermis, but into a hole in the base body that had previously been made to some extent. French products of this time can therefore be easily recognized by the exposed inside of the artificial eye and thus by the "translucent iris". Müller-Uri, on the other hand, placed his finished irides, like his painted with enamel paint, on the glass body sphere covered with a base layer.
The invention of cryolite glass
Müller-Uri also continued to look for a permanent white glass that came close to the scleral color. It should be able to withstand the discharge of tears permanently and have more naturalness and suppleness in the processing. The key to solving this problem lay in the joint work of the eye artists, especially Friedrich-Adolf Müller with the glass masters Septimius Greiner-Kleiner , Christian Müller-Pathle and August Greiner-Wirth : By clouding the glass with the newly discovered Greenland mineral ice stone (sodium hexafluoroaluminate) , the so-called cryolite glass was invented (1868). "The experts tested the new material" and immediately recognized the advantages of the new Thuringian glasses: The lightness and durability of the cryolite glass eyes was amazing in terms of wear compared to the Parisian eyes.
Building on the development of cryolite glass, there was a further essential refinement of the artificial eye around 1885. By replacing the “oil lamp” with a gas burner, it was possible to create a naturally washed-out “iridoscleral edge”. The eyes produced up to this point did not have this naturalness. A special melting process with supple cryolite glass results in the smooth transition from the cornea to the sclera , which is more or less clear depending on the age. With regard to the types of glass, it is also worth mentioning that crystal glass with the same melting base as the cryolite glass could be integrated to better represent the anterior chamber. The brands Müller-Uris and others who had meanwhile been initiated into this art had achieved a high level and international reputation in the 1880s.
Ludwig Müller-Uri himself was not lacking in recognition. Albrecht von Graefe , who has the merit of having established ophthalmology as a sovereign subject, was one of his customers and admirers. Even in the earliest years of ophthalmic prosthetics originating in Thuringia, the interaction between the eye artists of the time and the ophthalmologists should be emphasized. Müller-Uri was honored with first prizes at world exhibitions in Vienna (1873) , Philadelphia (1876) , Sydney (1880) and Melbourne (1881) . His artificial eyes were duly honored by "his sovereign", the "theater duke" Georg II (Saxony-Meiningen) , in 1878 with the silver medal and in 1887 with the gold medal of the Ernestine House Order for Art and Science. After this successful life, Müller-Uri died in his hometown in 1888 at the age of 77.
In the course of time, Müller-Uri had introduced his sons and a few relatives to the secrets of his eye glass blowing art, so that various companies were founded in Germany before 1900. The eldest son Reinhold stayed in Lauscha and took over the father's business. Son Albin founded his own company in Leipzig in 1893 , which was to be followed by the cities of Jena and Berlin in 1912 through his sons Ludwig and Otto.
Cup eye and reform eye
In the first 50 years of German eye prosthetics, at the request of the leading doctors Bühner and Ritterich, all artificial eyes were made in the same simple, single-walled thin shape according to the French manufacturers. In daily practice it turned out that voluminous artificial eyes are more useful in many cases. The company founded in Wiesbaden in 1872 by Friedrich Adolf Müller-Uri, a nephew of the Lauscha inventor, promoted the development of corpulent eye shapes on the initiative of the Dutch doctor Prof. Snellen (Utrecht). These "artificial eyeballs", also known as Snellen eyes, were called "reform eyes" from around the turn of the century. Since Ludwig Müller-Uri had already produced his first artificial eyes in a double-walled manner in 1832/33, this now improved method could be adopted by “all eye artists” and “reformed” artificial eyes produced. This new development made it possible not only to make artificial eyes thicker, but also to shape the shape of the artificial eye or its back according to the corresponding proportions of the orbit. The consequences were that the rounded edges led to a more comfortable fit of the prosthesis, the insertion and removal of the artificial eye became more uncomplicated, and maintenance was made easier.
At times, almost two-thirds of the conventional bowl was displaced by the reform eye. It is only through the increased use of hydroxyapatite implants today that cup eyes, especially scleral cups, are being used again for larger implants .
Cryolite glass as the dominant material for artificial eyes
Only special glasses are used for today's artificial eyes, which are produced exclusively for eye prosthetics. Since a large number of different types of glass are required for the production of artificial eyes, approximately the same meltability must be achieved by using different enamel raw materials. All glasses used for the respective artificial eye must be well connected and should therefore come from the same work. The continuous development of glass art was the inspiration for the development of the artificial eye. The Thuringian way of glass production from the Wanderglashütte to the founding of the Mutterglashütte zu Lauscha in 1597 with its constant further development and expansion of its product range from apothecary glass to filigree synthetic glass products was the prerequisite for the high art of artificial eye blowing. Today's artificial eye made of cryolite glass, each one unique, optimally meets medical requirements thanks to its hard, smooth and easily wettable surface, its unique ability to precisely adapt to the anatomy of the individual and its biocompatibility. The glasses are tested for body tolerance. With normal use, no irritation of the orbit occurs due to the tissue neutrality of the glasses. Only the cryolite and crystal glass come into contact with the conjunctiva. All other diverse, mostly colored alkali silicate or calcium phosphate glasses are literally melted down. The mirror-smooth exterior of the artificial eyes enables irritation-free movement of the eyelids. The artificial eye "swims", so to speak, in the conjunctival sac in the tear fluid. The mechanical friction is minimal. The mentioned properties of the glass eye prosthesis and its fire-polished surface allow a medically and hygienically perfect cleaning. If the wearing time is reasonable, there is no need for lubricants. The plastic is finding its way into ophthalmic prosthetics worldwide. The glass artificial eye, as it was developed and further developed by Ludwig Müller-Uri and his descendants and found its distribution all over the globe (Europe, USA, Canada, South America, Australia), is only important in Central Europe today. Although eye prostheses made of plastic - polymethyl methacrylate (PMMA) - have major disadvantages compared to the material glass - they can only be cleaned incompletely; their surface is water-repellent, gets rough faster and can be easily damaged; Even scarcely noticeable scratches lead to irritation of the conjunctiva - they displace the glass eye worldwide. One of the main reasons is certainly the requirements that must be met to manufacture glass eyes: this certainly includes the extraordinary skill of ophthalmic prosthetists and ocularists as well as their extremely long training period of at least 5 years to be able to manufacture eye prostheses from glass. The patient can effortlessly counteract the only disadvantage of the artificial eye made of glass, its fragility, by literally guarding "his" individually made artificial eye like the apple of his eye.
literature
- R. Hoffmann: Thuringian glass from Lauscha and the surrounding area. Seemann, Leipzig 1993, ISBN 3-363-00580-6 .
- M. Klaunig: The artificial eye. Wiegand, Leipzig 1883.
- G. Lehmann: The Lauscha glass industry. Dissertation . Heidelberg 1923.
- Albin Müller-Uri: The artificial eye. Leiner, Leipzig 1902.
- Friedrich A. Müller, Albert C. Müller: The artificial eye. Bergmann, Wiesbaden 1910.
- Fr. Phil. Ritterich: The artificial eye. Leipzig 1852.