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Ergo 101: Choosing the correct custom loupes as a dental hygienist

March 15, 2017
Cindy Purdy, RDH, explains the steps for a dental hygienist to acquire the correct loupes for the dental setting.

By Cindy Purdy, BSDH, CEAS

You probably have loupes from hygiene school, but are they the correct ones for you? Are they custom fit or “off the rack”? Are you still aching at the end of the day? If so, your loupes may be part of the problem.

Let’s think through this whole process. Magnification of the oral cavity is a great benefit of loupes, and the main purpose for loupes is to assist in maintaining your neck and trunk in a healthy, upright neutral position. Neutral position is defined as that bodily position where all structures—spine, bones, discs, muscles, tendons, ligaments—are in their strongest, most stable position. When properly fitted, a high-quality, custom loupe can be extremely beneficial in assisting to maintain your neck and shoulder in a neutral position.

Precise measurements

To maximize the benefits of a custom fitted loupe, a representative will obtain a variety of personal measurements related to facial geometry, inter-pupillary distance, working distance, eye prescription, and declination angle. All measurements are critical but the two measurements that will most assist in maintaining neutral position are:

  • Working distance
  • Declination angle

Working distance is defined as the distance from your eyes to your working target, or the patient’s mouth. Once this measurement is built into your oculars, it will determine the focal point of the target—basically, where it is in focus.

Declination angle refers to the amount of downward slope in the magnification oculars, as they are mounted into the carrier lens of the frame. In many circumstances, the amount of declination that can be achieved for any given loupe is determined by the design and shape of the frame that is holding the specific carrier lens. Those carrier lens that slant inward, toward the face, already have some declination built into them, versus those that are flat in design.

Both measurements can be controlled to maximize a healthy ergonomic outcome. A longer working distance may help to keep the head and neck in a more erect, upright spine-supported position, thus reducing forward head positioning. A steeper angle of declination angle of the oculars can assure less of a downward angle of the clinician’s neck and, thereby, allowing relaxation of the neck and shoulder muscles.


The risk for musculoskeletal injury increases as we bring ourselves outside of neutral position more than 20 degrees in any plane. This angle is very difficult to self-report because we clinicians are accustomed to adjusting our bodies to our environment. The definition of ergonomics is finding the best possible match for the greatest number of people by adapting the productto fit the user, not the other way around. To achieve a more accurate assessment of a healthy neutral neck position, it is best to employ the Buddy System. Ask a friend to snap a few side photos of you with alternate working distances. This will allow you to view your ideal head and neck positioning.

Education and experience

The experience of a trained loupe representative will come into play at this point. They will be able to assist in determining the correct magnification level, per the necessary width needed for your field of view. Field of view is how much area can be seen through the oculars. Ergonomically, it is best to have a wider field of view so as not to be moving your head from side. They will also be able to use your working distance to control the depth of your field of view. This is the depth of the focus in the viewing area. Ergonomically, it is best to have a wider field of view and the deepest depth of field to reduce repetitive movement of your head up/down or side-to-side when viewing the entire oral cavity.

The eyes have it

After these critical measurements have been made and your representative has determined they have given you the most ergonomically correct loupe for your facial structure, then you can choose that beautiful frame color that best matches those gorgeous eyes!

Cindy Purdy, BSDH, CEAS, says that 37 years of clinical dental hygiene has fueled her passion for workplace wellness. She holds an ergonomic certification from Colorado State University. In 2013, she earned her certified ergonomic assessment specialist credential, with emphasis on improving the health and performance of dental professionals by creating safe, in-office workstations. Cindy provides corporate consulting, training & strategic development for multiple ergonomic dental product manufacturers. Additionally, she provides ergonomic education for dental hygiene students throughout the country. Her current focus is to bring her CEAS skills into individual offices to increase the health of dental professionals and to reduce the number of careers that are cut short due to work-related musculoskeletal injuries. She can be contacted at [email protected].

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