How Prescription Lenses Were Made by Hand: Traditional Optical Lab Techniques

Before modern automation, prescription lenses were made almost entirely by hand. As part of opticianry training, students were required to learn how to make lenses manually, understanding every step of the process.

The process began with knowing the curves—both the curve required for the prescription and the curve of the tools being used. The correct tool would be mounted, combined with the appropriate grinding or polishing compound, and then run back and forth across the lens surface. The optician controlled the pressure, movement, and timing manually, while continuously applying solution and abrasive material to shape the lens.

In some cases, slightly more automated equipment was used, particularly technology developed in the 1950s and 1960s. Even then, the process still required constant hands-on involvement. Lenses were shaped and polished through repetitive motion, guided by the optician’s experience rather than a computer.

This was how glasses were truly made at one time—everything done by hand. Compared to today’s standards, it was a demanding and time-consuming process. However, it offered a deep understanding of how lenses behave and how small adjustments could change optical performance.

Interestingly, some of this older equipment can still be useful today. Manual polishing machines can sometimes be used to remove scratches, re-polish lenses, or perform specialty work such as fasten-on lenses or decorative diamond-cut edges, which were popular in the 1970s and 1980s.

While this type of technology is considered obsolete in 2025, knowing how lenses were once made by hand provides valuable insight into optical craftsmanship. It highlights the skill and knowledge required before automation—and why understanding the fundamentals still matters, even in modern labs.

Modern optical labs have evolved significantly from these traditional methods. In our next article, we look at how prescription lenses are made today.