troubleshooting tips
A High-Minus Plan
Karlen McLean, ABOC, NCLC
This simple approach to dispensing high-minus Rx's can help you achieve the best results. The following tips from Jonathan Schwartz, vice president of manufacturing at Pro Fit Optix in Grapevine, Texas, will help you hone your high-minus skills to ensure top-notch outcomes.
Q I recently gained a working relationship with a doctor who sends me a lot of difficult Rx's, specifically high-minus work above the −15.00D power range. I want to ‘wow’ her with fantastic lens results. What can I do in my dispensary to ensure the finest outcomes?
LENSES
A Take monocular PD measurements using a pupilometer or other quality measuring device. Consider vertical decentration if the frame's geometric center is more than three to five millimeters from the patient's pupil height (as with horizontal decentration, it's best to avoid this with a good frame fit).
Remember that 1.67 index lenses are available in a good selection of low- to minus-base fronts, and when surfaced with digitally controlled inside aspheric curves, they provide the widest range of minus powers while maintaining the best combination of optics and cosmetics. AR over quality hard coating is a must. Blended myodisc semi-finished blanks would be a good solution, or labs utilizing software to produce a digitally surfaced aspheric blended myodisc type of design.
EDGING
A Keep the front of the lens in line with the front of the frame to avoid protrusion of the lens thickness to the front. The flatter the curve of the frame chosen, the easier this is to accomplish.
The latest edging technology is capable of producing customized high-curve bevel designs with tilt or incline and step-back controls to help minimize lens edge thickness and secure the lens into the frame. A satin edge polish rather than a very high luster helps minimize the appearance of the lens' edge without causing internal reflections.
Some patients may prefer an edge coating on the lens to match and blend the lens into the frame, and light colors can be used for a cosmetic “tint” effect. Roll the edges on the inside moderately, only as needed, to properly close the temples. EB
| FRAME SELECTION |
|---|
| A Have a nice selection of smaller sizes that are designed specifically for high-minus prescriptions. The right frames are built to hold and hide low- or minus-base lenses and can minimize or eliminate decentration with balanced shapes—the rounder the better. Additionally, a good frame design will compensate for narrow width with extended temples. Complex frame shapes and sizes make it more difficult for a lab to produce a well-glazed product, so keep it simple. |
If you have a question you'd like to have answered in Ask the Labs, send it to Karlen McLean. Email: Karlen.Mclean@WoltersKluwer.com. An archive of past Ask the Labs columns can be found on the Eyecare Business website at www.eyecarebusiness.com.
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