INFORMATION FROM ADOLF'S 1960 PAPER,
AS TRANSLATED BY BRIGITTE.
Subject: Early Technical History of the System Mueller-Welt Contact Lens.
What follows, is a direct translation from the German of a paper written by my father, Adolf Wilhelm Mueller-Welt, in 1960, the year in which he and my mother returned to Germany from America to manage the vastly growing business under the supervision of optical engineer Helmut Polte and Brigitte. I have translated this information in as practical a manner as is reasonable for the technical aspects to be retained.
"Around the year 1900, my father, A. Albin Mueller-Welt, an artificial eye maker, blew his first scleral lens. It was made from Cryolite glass with the crystal lens in the cornea zone fused together. Unfortunately, it was an artistic work without any optical foundation. He made 70 to 80 of these before one could be used. Nevertheless, his success was much larger than lenses made by Herschel or Sulzer. The difference lay in the specifications; one was a contact lens the other a Haftglass. I have to stress the difference. A contact lens lies on the eye whereas a Haftglass has to be filled with fluid so that it will form a suction of the eye.
Technically, glass was implemented in many different ways. They tried to flow the glass in clear material. In other words, the root of the glass blowing was eliminated in order that the crystallens turned 90 degrees on the sclera glass bellows where it was mounted and then it was melted. This technique helped us later when we used crystal rods, because if the sphere wasn't turned while flowing, a root would have formed.
In our first patent, DRP. Nr. 553842 this question was raised, but it really only had to do with the first usable solid optical forms. The patent was given notice in 1928 and was registered in 1930. During those years I continued to produce my lenses and many other people were able to copy some of the mechanics of my lenses. Too many opponents wanted evidence of its prior use. There were more misunderstandings than there were any basis for them. They believed that I wanted the patent because I wanted to copy the form of the eyes in the sclera while only the curvature of the optical corneal zone stands in the forefront.
Nothing caused discomfort with my contact lenses, but when wearing the Haftglasses, even with chemical solution, it became extremely uncomfortable. Even with the finest glass that was optically perfect it brought no more comfort. The reason for this was that a foreign material had no resistance against the tearfluid. Many trials were made before a satisfactory material came from Schott in Jena. Finally, there was success. Many other difficulties were because of faulty optical mathematics. Today one can say that the vertical heights and the optical zone diameter of the lens were already correctly constructed. The changes and refinements came about naturally with development of proper techniques.
There was a greater task at hand, the correction of the spectacle in the curvature of the lens saw much work on this at the university clinics. With the willing help of Professors like Siegrist, Heine, Sattler, Stock, and others, especially with their examination results and reports, many mistakes were found. There were many mistakes cited that had completely different reasons than were thought of before. The cornea erosion was not the result of the lens lying on the cornea, but through roughness of the dryed-out tearfluid or dirt that had worked its way under the lens. Wrinkling of the cornea came about through too strong convexed inner curves and oedema through too much fluid sediment.
With knowledge of the anatomical form of the eye, one could encounter quite a few surprises. Firstly, and most surprising, is that the optic is not in the middle of the cornea . Instead, it is in the right corner towards the middle of the line of sight. What we have then, is a mostly an elliptical or modest outer shape. Secondly, we have also, without a cylinder in the optic zone, mostly an asymmetric interim zone that almost always is horizontal rather than vertical. Because of this, a swing movement occurs. The latter can sometimes lead to buoyancy. In most cases, one has to equalize this.
Up to now, I have described all that was known up to 1936. In the years that followed we got busy with the technique of grinding and polishing and used those to improve the tension in the material. As far back as 1913, an artificial eye maker gave Zeiss, in Jena, 100 lenses to have Zeiss grind and polish them, but all of them broke under the tension. Why that happened nobody ever figured it out. The glass technique in those days was already quite advanced. The only plausible explanation was that perhaps the cryoliteglass, when not handled with extreme care erupted ten days after being finished, making it rough on the surface. This was simply not recognized.
However, I was successful in diminishing the tension in those lenses. Soon, even better clear crystal glass was developed. Nevertheless, in the beginning this was only possible because in my Stuttgart testing laboratory I was able to make many test trials. Thin ones broke easily and thick ones broke very slowly. A mixture of the two proved to be the solution. It was much more durable. Finally we had the material for producing reliable contact lenses.
A professor at the Technical Highschool once said to me: "Observe, without tension you cannot produce glass, but by relaxing the tension to the extreme, hot and cold doesn't effect it.. The material can still be kept hardened or soft without again becoming tense." This was helpful in mitigating the influence of tearfluid.
Grinding and polishing is easier and more effective if the material is hard. Grinding and polishing was not a simple operation. After all, we were dealing with micro optics. Difficulties in grinding and polishing arose out of the complex radien where the grinding part is arched more than the outer. The old and experienced grinders knew this and kept it to themselves. They were the tricks of the trade. We had to pay handsomely for this information, as is always the case when someone needs information that another person has.
Using a 12 spindle machine that we made ourselves we first ground the optics. Then the edges were ground. They were then softened and again relaxed. That is how we were able to easily turn out sets of 5,000 to 6,000 glass lenses in a short time. Now that we were on top of the process of manufacturing vast numbers of fluidless glass lenses I had to develop a sure and continuing market for my product. The answer was in extensive, personal travel throughout the Germanic countries. We had great success in Berlin, Kiel, Koenigsberg, Breslau, Leipzig, Cologne, Vienna and especially in Munich where great interest was shown.
In the early days, ophthalmologists showed the
greatest interest. Eventually the new lenses gained the attention
and approval of opticians.