Selecting Loupes and LED Headlights for the Best Vision and Ergonomics

ErgoPractice News – May 2015

SurgiTel was founded in the early 1990s as a Division of General Scientific Corporation to help clinicians practice safely. SurgiTel has accomplished this by providing clinicians with ergonomic loupes, portable headlights, and related products such as stools, eye-protection filters, and loupe-mounted video cameras.

During the last two years, SurgiTel’s ErgoPractice News has reported advances made with loupes and headlights during the last twenty years1-5 and discussed the key issues related to the ergonomic practice of dentistry and surgery.^6,7 Today, with SurgiTel’s advanced loupes and achromatic LED headlights, clinicians may achieve the pain-free ergonomic practice. Clinicians can minimize the tilt of their heads with SurgiTel’s custom declination angle loupes and the greatest number of magnification options. And they can achieve the best visual acuity with achromatic LED headlights that offer the best color accuracy and are the safest to the eyes.^8,9 This issue will review how to select the best loupes and LED headlights for you.

SurgiTel Loupes

In 1993 SurgiTel introduced the first, truly ergonomic Front-Lens-Mounted (FLM) loupe. SurgiTel did this by inventing and patenting a unique ocular-mounting assembly with double hinges and vertical adjustability slide.¹ SurgiTel’s adjustable FLM loupes allow users to optimize the declination angle of loupes and can optionally be flipped up for direct vision.

Through the years, loupes with non-ergonomic, small declination angles have continued to be a major cause of chronic neck pain or injuries. SurgiTel delayed the introduction of any Through-the-Lens (TTL) loupes until SurgiTel created its own titanium frames, with larger pantoscopic angles and double nose pads. These patented features allowed SurgiTel TTL loupes to have far larger declination angles than traditional designs (Figure 1).

Recently, SurgiTel developed an advanced assembling method for TTL loupes to achieve very steep declination angles (patent pending). SurgiTel is now able to offer our customers TTL loupes with declination angles up to 55 degrees (Figure 2). This has allowed us to serve the greatest number of clinician’s ergonomic needs, including some clinicians who have already suffered an injury from using non-ergonomic loupes.

SurgiTel offers the most complete range of loupe magnifications, available in both TTL and FLM styles, from 2.5x to 8.0x. SurgiTel’s product lines include the Micro Line, the Compact Line, and the Prism Pro-Line. See the sidebar “SurgiTel Magnification Options” for the full list of SurgiTel ocular choices.

Questions when Selecting Loupes

Clinicians who are selecting loupes often have similar questions. We will answer some of the most common:

Question: What benefits do ergonomic frames offer for either FLM or TTL loupes?
Answer: SurgiTel’s ergonomic frames are built with special requirements, such as increased pantoscopic tilt. SurgiTel’s Oakley frame selections also meet these requirements. These frames allow SurgiTel loupes to have a larger field of view and larger declination angles than the traditional designs in the market.

Question: Who may choose customizable FLM loupes and why?
Answer: SurgiTel’s customizable FLM loupes allow users to optimize their declination angles and provide good direct vision. FLM loupes have been preferred by clinicians who: 1) want both magnified vision and good direct vision, 2) want to have larger declination angles to alleviate their neck pain or to avoid potential neck pain/injuries, and 3) have low noses and find their eyelashes touch their TTL oculars.

Question: Who may choose TTL loupes and why?
Answer: TTL loupes are slightly lighter than FLM loupes when the same oculars are used. It should be pointed out that SurgiTel’s micro FLM loupes are significantly lighter than traditional TTL loupes. Oculars of TTL loupes are closer to the eyes and thus users with high noses will achieve a larger field of view. Clinicians with low noses will not achieve a larger field of view but they will experience a larger scotoma (blind spot) between the magnified field and their peripheral, direct vision. Clinicians with low noses may instead prefer FLM loupes.

Question: What are the main benefits of compact prism loupes over traditional prism loupes?
Answer: Compact prism loupes are shorter and lighter than traditional prism loupes. With compact prism loupes, users can also achieve a larger field of view.

Question: Why did SurgiTel add micro line loupes in addition to compact line loupes?
Answer: Micro line loupes use smaller optics and the weight of micro line loupes is significantly lighter than compact line loupes. A compromise is that micro line loupes require brighter illumination. Clinicians with well-lit operatories and who want lightweight loupes may prefer micro line loupes.

Question: Who may choose SurgiTel’s EVX250 or EVC250 models?
Answer: As working distance increases, the effective magnification power of loupes decreases, and the field size increases.⁴ SurgiTel’s EVX250 is designed for clinicians whose working distances are relatively short (sitting working postures for example), but want a large field of view. SurgiTel’s EVC250 is designed for clinicians whose working distances are relatively long (standing working postures), but want good visual acuity at long working distances.

Question: Why can SurgiTel loupes be used as multiple magnification power loupes?
Answer: The effective magnification power of loupes will increase as their focal length decreases.⁴ The focal lengths of all SurgiTel loupes can be altered by using working distance adjustment caps for Galilean loupes or working distance caps for prism loupes. Therefore all SurgiTel loupes can be used as multiple magnification power loupes.

SurgiTel Headlights

SurgiTel offers three portable LED headlights and two loupe-mountable fiber optic lights. SurgiTel LED lights to use multiple precision optical systems (patented or patent pending) which create a uniform, achromatic beams.⁵ See the sidebar “SurgiTel LED Headlight Options” for the full list of SurgiTel LED lights and features.

Questions when Selecting Headlights

SurgiTel micro/mini LED or fiber optic headlights can be mounted onto SurgiTel’s FLM or TTL loupes and also onto all major brand loupes. SurgiTel headlights can be mounted onto headbands which can be used along with any loupes. The April 2015 issue of ErgoPractice News pointed out the advantages of SurgiTel’s achromatic LED beams over traditional dispersed LED beams (Figure 3) and reviewed questions associated with LED headlights.⁵

Clinicians who are selecting Headlights often have similar questions. We will answer some of the most common:

Question: Why achromatic LED beams?
Answer: The achromatic beam does not have color dispersion and glare. The beam color does not change no matter the working distance range. Therefore, the achromatic beam offers the best color accuracy and is the safest to eyes.^7,8 Traditional LED beams have dispersed colors that create a blue tint around a bright center spot and creates glare. Also, the beam patterns change over the working distance range, resulting in the discoloration of objects.

Question: Who may choose Micro or Mini neutral LED lights and why?
Answer: Clinicians who wish to see the most natural color of anatomical objects choose neutral LED lights. This may be important for cosmetic procedures.

Question: Who may choose Micro or Mini cool LED lights and why?
Answer: Clinicians who want to enhance the blue color of certain anatomical features such as veins. Certain surgical specialties may prefer this type of light.

Question: Who may choose Fiber Optic lights and why?
Answer: Many of the traditionally designed fiber optic lights are heavy, headband-mounted, and designed to work with traditional loupes with small declination angles. Therefore, these traditional fiber optic headlights cannot be used with ergonomic loupes with large declination angles. SurgiTel developed two fiber optic lights: a) wide field and b) high intensity. Both are small and light enough to be mounted directly to nearly any loupe. SurgiTel fiber optic lights with ACMI adaptor can be used with most surgical light sources.

Question: How can I enhance my LED Headlight’s performance by adjusting the brightness of the operatories’ overhead lights?
Answer: Even the brightest light will disappear under a bright summer sun. This is because our eyes are sophisticated optical devices that adapt to their environment and our perception of ‘brightness’ is relative. The pupil size of our eyes in a dark environment may enlarge to as much as 8mm. But in a bright environment, our pupil size may shrink to less than 1mm. Therefore, the light collection efficiency of eyes in the dark is more than 64 times that of eyes under the bright sunlight. Clinicians have found that reducing the brightness of overhead lights has a dramatic effect on the perceived brightness of an LED Headlight.

We hope this white paper has served as a quick and useful introductory guide to selecting loupes and LED headlights based on vision and ergonomics. But for customized service, you should seek the assistance of your local SurgiTel representative to determine what tools will work best for you and your office. You may contact your local representative at www.SurgiTel.com/MyRep

References:

Chang, BJ, Demystifying Custom Loupes, ErgoPractice News, October 2013; https://surgitel.com/demystifying-custom-loupes/
Chang, BJ, Advances in Magnification and Mounting with SurgiTel Patented Prism Loupe Technology, ErgoPractice News, February 2014; https://surgitel.com/advances-in-magnification-and-mounting-with-surgitels-patented-prism-loupe-technology/
Chang, BJ, Advances in SurgiTel Headlights: Design Considerations of LED Headlights for Color Accuracy and Eye Safety, ErgoPractice News, March 2014; https://surgitel.com/advances-in-surgitel-headlights-design-considerations-of-led-headlights-for-color-accuracy-and-eye-safety/
Chang, BJ, Demystifying Magnification Power of Loupes: 7 Questions and Answers, ErgoPractice News, March 2015; https://surgitel.com/demystifying-magnification-power-of-loupes-7-questions-and-answers/
Chang, BJ, Demystifying LED Headlights: 7 Questions and Answers, ErgoPractice News, April 2015; https://surgitel.com/demystifying-led-headlights-7-questions-and-answers/
Chang, BJ, ADA 2013: Health and Fitness: Lectures Highlight Ergonomics, ErgoPractice News, December 2013; https://surgitel.com/ada-2013-health-and-fitness-lectures-highlight-ergonomics/
Chang, BJ and Karl M Schwartz, Can Chronic Neck Pain Be Eliminated or Healed? Selected Testimonials and Ergonomic Courses, ErgoPractice News, April 2014; https://surgitel.com/can-chronic-neck-pain-be-eliminated-or-healed-selected-testimonials-and-ergonomic-courses/
Clinicians Report, Small and Lighter ELD Headlamps, A Publication of CR Foundation, April 2012, www.CliniciansReport.org
Clinicians Report, Is your LED headlamps damaging your eyes?, A Publication of CR Foundation, March 2013, www.CliniciansReport.org