This blog doesn’t just cater to the consumer. It also has information that helps opticians, lab technicians and sales associates. If you’re a lab tech and responsible for manufacturing eyeglasses in a full surfacing lab, then from time to time, you’re going to experience having swirly lenses come out of surface side.

Here are a few tips that will help you troubleshoot what is going on and hopefully eliminate the problem very quickly. Feel free to add to these tips by leaving a comment at the bottom of the page. These are basic tips that can help you figure out why you are having swirl marks on your uncut lenses. Many of these checks are simply common sense items that tend to get overlooked. For more complicated issues you might consider checking with your equipment manufacturer or internal lab equipment technical support department.

1. If you are using a manual generator such as a Gerber 108, Gerber 108 CT or a Gerber 113, take a moment to check your curves. You can do this by blocking up a 6 base CR39 plastic lens. Use a lens clock to check the true curve, is most cases you’re looking at 6.25 base. Chuck the lens and proceed to take a few passes of material off cutting at the same curvature. In this example, 6.25 / 6.25. Unchuck the lens and take a red color grease pencil and color the entire back surface of the lens and then set the lenses back into your job tray.
2. Pull your laps and then measure the true curvature. Take a reading at your 90 as well as your 0 / 180. Your lap tool should measure accurately or within a few tenths of a diopter. If the tools are off then you’ll need to reselect another set until you find an accurate set. The ones that you find to be inaccurate either need to be restamped according to their true reading or thrown away. Don’t forget to reorder.
3. Once you have your proper lap tools, apply a first fine (rough grit) pad and then chuck the tool and the test lens on the finer. Run the finer for about 15 seconds at 12 PSI and then unchuck the lens and take note of grease pencil marks. From here you’ll be able to check and see if the finer is finding in properly and you’ll be able to run out that the generator is running either too steep or flat on the curves.

It is possible that you might need to recalibrate your generator. Refer to your user manual for instructions on how to do this. If you don’t have a user manual, I am in the process of trying to find a PDF versions of the most common generator types and will be uploading them soon. Check the manufacture or contact your internal lab support team.

Sometimes swirls happen due to other things not so complex. Sometimes problems can be very simple and easily overlooked.

1. Check your lap tools for accuracy
2. Check your cylinder machines for proper pressure (both finers and polishers)
3. Are you touching off the edges of your lenses after they come off the generator?
4. Are you running a very slow and smooth final pass on the generator?
5. How much material are you taking off on your final pass? (no more than .5MM @ 5 second pass)
6. What condition or how many cuts do you have on your generator blade?
7. When was the last time you changed the pins on the cylinder machine?
8. Double check your orbit, stroke and axis settings on the clyinder machines. (very important)

Does the problem only occur with certain materials? Does this problem only happen with minus lenses or plus lenses? Think smart and play detective and make sure everything and all equipment is running according to your lab equipment guidelines. Once you have all your equipment in top running order, then you can effectively troubleshoot. And 9 out of 10 times, when you revisit your equipment calibrations and standard configurations, the problem resolves itself.