Contact lens manufacture — A world review

Abstract

Last year's Presidential Address represented a very thorough review of the development of contact lens fitting from its earliest beginnings to its current state of complexity. I hope to attempt a similar review of the parallel development of manufacturing techniques and to give some indication of likely trends into the 1980's. It is self evident that the development of contact lens design and manufacturing capabilities are largely symbiotic. In fact, in many cases, the same people were involved in both processes. Many early practitioners were forced to turn themselves into engineers and technicians in order to convert a concept into reality, and those concerned in the early development of contact lenses were drawn from a wide spread of disciplines. The original development of contact lenses was well reviewed on this occasion last year and is sufficiently well documented to be generally accepted. The earliest fabrication process involved blowing glass lenses to conform to moulds, and, subsequently, grinding and polishing lenses from glass to the desired configuration, exactly as a spectacle lens is generated today. George Nissel's research of several years ago shows us that whilst the Wiesbaden firm of Muller was, towards the end of the last century, blowing glass lenses, Carl Zeiss were grinding and polishing them. It would appear that while the blown lenses, as fitted by Drs. Fick and Kalt, were well tolerated, probably because the manufacturing method would result in a finer surface finish, they were not always as optically accurate as could be desired. This is not surprising as with this lens, both the scleral fitting area arid the optical power were blown and the required accuracy could not always be achieved (Fig. 1). The ground and polished lens, on