Lab Equipment in the 21st Century
New surface generators and
in-office edgers will improve the quality
and accuracy of ophthalmic lenses.
BY JAMES J. KIRCHNER, O.D., F.A.A.O., Lincoln, Neb.
As you've undoubtedly noticed, our industry is changing. We see technological advances in almost all areas of optometric practice. For example, new diagnostic instruments seem to pop up at every turn and new therapeutic agents treat diseases while causing fewer side effects. But an area of our industry that's on the verge of unnoticed historical change is the wholesale optical laboratory.
Let's see what the future holds for wholesale labs and in-office operations.
In your office
Manufacturers are developing new technology in the finishing area. The latest edgers are capable of not only loading themselves with the aid of robotics, but can edge lenses to size and shape, apply pin bevels, and roll and polish the edges at a single stop. If the machine is designed appropriately, labs can also drill holes automatically for drill-mounted prescriptions. All of this automation with one piece of equipment! This technology can be found in some of the latest edging equipment that's available for in-office labs.
The way we send job orders to the laboratory is also changing. We now have the technology to allow the electronic transfer of order data and the lens (frame) shape information (derived from frame tracers) directly from your office to your lab host computer. This eliminates order data entry errors, gets your work in progress much faster and provides more precise information so that the lab equipment will be set more accurately.
The next big thing
Our lab partners have given us years of reliable service and quality products. While they have provided continual changes in technology as well, they're now preparing for some major advances. First and foremost is the development of "free-form" technology in the production of prescription ophthalmic lenses. To understand this change, we need to look at how labs have produced lenses historically.
A glimpse of the past
The initial step in producing prescription ophthalmic lenses utilizes partially prepared lenses called semi-finished blanks. The laboratory purchases these blanks from lens manufacturers in a variety of base curves formed on the front surface. In addition, if the blanks are multifocal (either in segment form or in progressive form), then this is formed on the front surface as well. The lab stocks the blanks in a variety of materials and refractive indices.
When the lab receives your order, it chooses a semi-finished blank based on the prescription information. The generator uses the calculations it receives to set the machine parameters, enabling it to remove back surface material from the lens to create the spherical and astigmatic power needed to fulfill the prescription. When the lab completes this process, the lens has a thickness and powers that are accurate, but in a roughened state.
The next step has been to use a tool called a lap to "fine" the lens. These laps are customarily made out of aluminum and have a rounded front surface. Labs stock them in progressive steps of different curvatures. The optician applies a rough granular pad to the curved surface of the lap so that it can be used to further remove material while polishing the generated surface of the lens. As mentioned, the lab produces laps in progressive steps of curvature, therefore we're getting approximately close to the desired curve, but usually not exact. Finally, the tech takes the lens to a polishing machine to smooth the surface.
Streamlining the process
The paradigm shift that we're about to see is a new generation of surface generators that take prescription information and produce custom lenses while eliminating production steps.
These new generators will receive information called points files from a host computer. The points files will set the cutting lathes on the generators to create precise prescriptions with a smooth surface. They're so accurate and the resultant quality so high that it's possible to take the lens directly to the polish step, bypassing the fining step. By eliminating fining, we can conceivably eliminate the use of laps.
In addition, these new surface generators will create customized progressive addition lenses (PALs) by generating the add power on the back side of the lens. It appears that progressive adds on the back surface of a lens is an improvement in quality that will create a whole new generation of PALS.
The sky is the limit when using points files to customize the production of lenses. It's possible to gather unconventional data from patients relating to their occupational and avocational needs, then use this information to produce custom lenses. The ability to take standard, semi-finished blanks and produce customized orders in-lab is the single most exciting prospect of the free-form production of ophthalmic lenses. It will reduce the inventories of semi-finished lenses that the lab will have to maintain, as well as decrease the turnaround time of the order.
Additionally, the lab can make the prescription with much greater accuracy and with a smoother surface. Several ophthalmic equipment manufacturers (see the box at left) have released first-generation models of free-form capable generators. More will undoubtedly follow.
Lab operations change as rapidly as the optometric practice. Wonderful advances will propel the evolution of ophthalmic lenses into more accurate, customized and superior products than we've ever seen. Combine these advances with the new materials being developed and the real beneficiary will be our patients.
Dr. Kirchner is president of Hi-Tech Optics and a senior partner of EyeCare Specialties. You can reach him at
The Latest in Lab Equipment
Optometric Management, Issue: March 2005