THE LEGACY LAB
First, what is a Legacy lab? I define it as a lens producing facility that uses processes that are centered on machinery and tooling that has been superseded by equipment and procedures in use in the last decade. A short list of the Legacy tools includes: manual lathes, 3 axis air-bearing CNC lathes, lens blanks in collets, tapered or screw-on blocking tools, spin blocking, pitch polishing, manual inspection, and manual order-entry and tracking. Some of these items are still in use even in productive labs; producing spheres and aspheres. Here are the effects of each of the above mentioned items:
1. Manual lathes: These lathes are limited in the lens designs that they can produce. The poor surface quality requires pitch polishing.
2. Three axis CNC lathe: These lathes are limited to corneal and mini-scleral designs.
4. Lens blanks in collets: This practice can result in poor centration control, distortion leading to poor optics and possible tilt leading to edge thickness variation problems especially with scleral lenses.
5. Tapered or screw-on blocking tools: These tools have poor security on the lathe spindle and internal debris affects prism control. Used with a collet blocker, this system can be prone to poor centration.
6. Spin blocking: This procedure is dependent on the skill and attention of the operator, and greatly limits the precision of the blocking process.
7. Pitch polishing: This procedure has many operator influences and is useful only for spheres.
8. Manual inspection: This process can be dependent on the operator.9. Manual order entry and tracking: The potential for lathe set up and date entry errors should not be underestimated.The continued use of these older items and practices can be a major source of reject lenses or may require substantial rework of the lens at final inspection. The rejects can range from prism, surface defects, and wetability problems, poor optics, radius/power errors, and data entry errors, among others.
This is not to say that the legacy lab doesn't invest in new equipment. I have seen labs that buy a new lathe, blocker, and polishers to an amount of a few hundred thousand dollars and then continue to use their old blocking tooling. The cost of new blocking tooling for a lab that is producing 100 corneal lenses per day would be less than $1000. New precision tooling gives the lab manager a repeatable process that can be validated. This will give the production manager control over the system comprised of the lathe collet, blocking tool, and blocking machine. By measuring radial run-out and making the indicated adjustment, precision control of prism will be realized.
Here is an example of legacy blocking tools. There has been a notion to use oversize blocking tools (see Global Contact #3, 2014). The reason for this approach was to provide a firm clamping force on the blocking tool while being able to place a lens blank in the same collet without needing to adjust the collet clamping force to provide a delicate force on the blank. The procedure does allow the use of one collet for both front curve and base curve production. The problem with this procedure is the over-stressing of the collet and the lens blank. In the case of the collet, the oversize tools may permanently damage the collet. In the case of the lens blank, clamping the lens blank can yield poor optics.
There is a secondary effect that the Legacy Lab has had on our industry around the world.
This effect has happened many times in technology transfers to developing markets. I have visited many labs where the owner partnered with a US or European lab to start a lab in their country. Visiting such a lab is like going back in time. Yes, they may have invested in new equipment, as I mentioned above, but they use the tooling design and the old processes, including pitch polishing from the parent lab. As with the example about the collet above, the "daughter" lab adopted the same collet/lens blank procedure. Even with new equipment, they were still having random prism problems due to the mis-match of the blocking tools and the lathe and blocker collets. I have found the resistance to improvement/change is greater in the daughter labs than in the parent lab.
Now let's compare the Legacy lab to a new start-up lab. I'm going to make some assumptions about the new (ideal) lab owner: She/he is:
1. Well funded.
2. Understands the market.
3. Understands the regulatory environment in the market.
4. Understands the need for a trainable production manager.
In the case of a new lab owner; going into the start-up process, this owner is looking into machinery and the process to produce both soft lens and RGP corneal designs. At some point in the future, they may produce scleral lenses, so it would be good to have an easy transition to that process. Their advantage, as I see it, is the unbiased and "no baggage" approach to the manufacturing process. We would recommend the machines and tooling and process to produce these lenses. The benefit to the start-up is that we will work with the production manager and staff to be trained in contemporary CL manufacturing practices; keeping in mind that in five to ten years new processes and/or machinery will dictate production changes in the lab. This means the lab owner can be assured of having a state of the art facility that can concentrate on the front office and sales, growing the company rather than managing the minutia of lens manufacturing. It is easier to leave that to the lab manager/support group partnership. By that, I am referring to the relationship the production manager has with the machinery/tooling/cosumables vendors.
Now, let's look at the start-up from the veteran lab owner's perspective. The concept of a start-up is foreign to most seasoned lab owners. If he/she were to consider the four points listed above, they might decide not to get into the business. But let's assume that they want to stay in. They may be considering a new location or a secondary production facility possibly in a different country. This could be an opportunity to train new people in contemporary lab practices as if it was truly a start-up. This would require that the lab owner accept the contemporary practices and hire a production manager who will promote them. This must be difficult, because I don't see that happening very often.There is a side benefit to adopting the contemporary process; if the implementation is successful, the lab owner can install it in the original lab.
The start-up culture is one of forward thinking process planning. It is a culture of improvement. I know of a few labs that maintain the startup culture. The goal is to improve the production level and or lens quality every year. Everyone in the company is engaged in the goal. One could say, with reason, that this is an unrealistic goal after several years. But the culture that is developed can stay in place and continue to generate a successful enterprise. One thing is for sure, this lab stays current.