Ask the Labs
ask the labs
Susan P. Tarrant
Q What’s the best way to remove a very tight lens from a grooved rimless mount without damaging the groove?
A If the lens is in the frame too tight, we will use two people to remove it. One person holds the frame tight and pulls on the temple side of the frame while the other person slides a ribbon between the lens and the line.
We use the strapping that holds our lens order boxes together by cutting it into strips about four inches long and about 4mm to 5mm wide. If that doesn’t work, we’ll cut the line with a razor blade at the temple side (lower hole) and restring. I have found that 30-pound fishing line works very well on most frames.
— Steve LaDuke, production
manager, Katz & Klein, Inc.,
Q When drilling for three-piece mounts, what should be taken into consideration when placing drill holes (bridge and temple)? To line them up horizontally all the time doesn’t seem to take individual face shape/nose height into consideration.
A When the lab gets a rimless frame from the ECP, we really do not know exactly how it fits the patient, so we follow the specifications and drill charts provided to us from the frame manufacturers.
We assume that the patient tried the frame on, it fits correctly, and PD and seg height measurements received from the ECP were based on the factory-supplied placement of the mounting.
If a chart is not available, we duplicate what the mounted demo lens has for drill points. The only time we deviate from this practice is when we receive requests from the account for special mounting placement of the bridge or temples.
When dealing with custom shapes or custom sizes in three-piece mounts, our suggestion would be to use a pair of trial lenses. If an ECP is unable to make the trial lenses for his or her client on site, we can help by
edging and mounting the trial lenses so the ECP can confirm the custom shape or size and fit with the patient.
Once any modifications have been made, exact measurements can then be taken with the trial frame for exacting results. Making trial lenses is certainly more work, but when done correctly, the end result is a superb fit that patients appreciate and deserve.
— Gerald Koolstra, vice president, operations, Pech Optical, Sioux City, IA
Q When using a hand edger for bevels, I have a difficult time getting all the shaved bits of poly (swarf) off the edges. Can you give me some advice? It seems to happen often when working with poly.
A The eyecare professional or lab technician should use a dry edger—not wet—and go in the same direction as the wheel. When done, touch up the edge with a wet wheel for a nice, clean look.
— Jean Pollard, customer service supervisor, Robertson Optical Laboratories, Inc., Columbia, SC
If you have a question you’d like to have answered in Ask the Labs, send it to Susan P. Tarrant. Email: Susan.Tarrant@Springer.com. An archive of past Ask the Labs columns can be found on the Eyecare Business website at EyecareBusiness.com.
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