EYE ON EQUIPMENT
Jobs on the Side...Bringing Tough Jobs In-House
By Joanne Lisa

Once bit, twice shy? Tried to tackle those hard-to-handle jobs in-house, only to break or ruin the lenses during edging? Still sending jobs out because you are unsure if, or how, they should be processed? Continuing to pay premium costs for work you can easily keep in-house? Look around your lab. How many trays contain jobs on the side?

Here, equipment experts take on your challenges and provide solutions to help you move these jobs from the side into the mainstream of your everyday in-house work.

EXECUTIVE BIFOCALS

Q I usually leave the edging of executive bifocals to the lab since I am often unsure how to achieve the correct placement of the height of the segment during edging. I'd like to process these jobs in-house. Can you provide advice on how I can ensure proper placement of the segment on executive lenses?

A Before you can begin processing, you'll need to determine whether the lenses you are working with are on- or off-center. Try this quick test to verify: Mark the distance and near optical centers. If they line up, the lens is decentered. If they don't line up, the lens has been processed off-center. To eliminate confusion in the future, take control of ordering your executive jobs and request them to be cut on-center. This will make your job of edging easier.

Due to the differing curves on an executive lens surface, the block doesn't always adhere tightly enough. Consequently, the lens will often slip in processing, resulting in a segment height that is incorrect. To get around this problem, one solution is to "trick" your machine into thinking the executive is a progressive lens. Try this different spin on edging to ensure accuracy with executive lenses and success every time:

1. Mark the distance optical center with a lensometer.

2. Before blocking, measure the difference between the distance OC and the executive line.

3. Place the block on the distance center marking.

4. In the PD section of the edger, enter the distance PD, not the near PD you would usually enter for executives.

5. At the height station on the edger, enter the height you require for the segment, plus the difference you measured in step 2 between the distance OC and the top of the segment.

6. Cut the executive job as a progressive lens.

For example, to achieve a segment height of 17mm, input the height of the bifocal (17mm) plus the distance measured from the OC to the top of the segment line (i.e. 7mm). That is, 17mm + 7mm = 24mm. Thus, 24mm is the number to enter into the edger.

--Rick Noonkester, regional manager, Santinelli International

HIGH PRISM AND CYLINDER

Q I have a hard time with the bevel placement on jobs with high prism and high cylinder. What is the most efficient way to edge these lenses and place the bevel?

A Use of a controlled bevel will achieve the results you desire. The key is to follow the shape and curve of the frame. If you know the curve of the frame, use it to determine the bevel placement.

For example: If the curve of the frame is in an 8-base, and the curve of the lens is a 4-base, choose a 6-base lens, and you will find that the frame will hold the lens in place. Also, you will have a better chance of achieving the proper placement of the bevel if you use a swivel or flexible clamping pad to accommodate the curve of the backside of the lens.

-- Michael Urban, manager, product
marketing, Gerber Coburn

GLASS LENSES AND LIABILITY

Q My business is located in a rural area where a large percentage of the population still prefers glass lenses, especially photo-chromic, for outdoor use. Now that glass is 10 percent of my business, I'd like to be able to handle these jobs in-house without worrying about liability.

How can I prepare my finishing operation to handle glass lenses properly and safely?

A If you are doing five glass jobs a week, or more, it pays to handle this work yourself. The key is to ensure that each of the following steps is followed and documented along the way.

Begin by purchasing an edger with a diamond wheel. Any diamond wet-edger will handle glass. This wheel will also cut CR 39 lenses. It pays to purchase a machine with as many wheels as possible, so you can handle all types of material. Shop around or consider sacrificing the capability of doing jobs in-house in a material you rarely have call for.

Once the lenses are cut, temper them with a heat treatment or chemical hardening process. Each manufacturer provides a chart for how to use and correctly set numbers on the units. To calculate the number to follow on the vendor chart, use a caliper to determine the thickest and thinnest portions of a lens. Add the two numbers together and divide by two. The resulting average of the two will be the number to follow on the manufacturer's chart.

And, finally, drop ball test the lenses with the proper equipment and document all the steps you have taken on the patient's chart, so that liability will not be an issue.

--Andrew Bumerts, south central
sales manager, Briot, Inc.

Round Bifocals

Q  have a few customers who have previously worn Kryptoc lenses and prefer to stay with the round bifocals they are accustomed to. Fearing difficulty in placing the segment correctly, I have always sent these jobs out. I'd like to try keeping them in-house in the future. Can you explain how I can ensure proper placement of the bifocal?

A Looks can be deceiving, and just the look of a Kryptoc seems to get these jobs sent out. But in reality, processing is very simple. Just follow these steps:

1. Mark the proper axis with your lensometer.

2. Line up the apex of the bifocal over the 180-degree line and make sure the lens axis (the line created by the three dots from the lensometer) is parallel to the same line.

3. If you are using a blocking device, place the round segment equally between the vertical lines.

4. If the blocking device is incorporated into your machine, follow the same steps and center the width of the segment between the vertical dotted lines.

--Bill Galindo, president, OD EB

Answers to more Jobs On the Side questions will appear in the next issue. If you have processing problems you'd like our panel of experts to address, send them to: Eyecare Business, 535 Connecticut Avenue, Suite 104A, Norwalk, CT 06854-1722; fax 203-838-2550.