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What is an Achromatic LED and Why is it Important?

ErgoPractice News – October 2017
By Jin Chang PhD

Gordon Christensen’s Clinicians Report recently did a study on Wireless LED Headlights.1 There was a wide range in beam uniformity as well as color temperature. You may wish to review this report on the Clinicians Report website because these are exactly the two factors that define how well an LED headlight will help your work!

In this month’s newsletter, we will further examine two requirements of LED headlight quality and safety.

Many more details on LED headlights are available in the November 2013 article of ErgoPractice News titled “Fundamentals of Clinical Illumination and LED Technology,” available on our website or view by Clicking Here.2

Light Quality and Your Work

You can do your best work when you see the greatest detail and the most accurate colors of your target. The clinician should also not be subjected to eye-health risks while using the light. These are the two minimum design requirements.

There are two primary qualities of a light beam: Beam Uniformity and Color Balance. These impact image quality and eye safety.

Beam Uniformity and Image Clarity

SurgiTel’s patented multi-lens system generates achromatic beams in our LED headlights. The achromatic, multi-lens system mixes all wavelengths of the LED light so they spread out evenly. This results in a clear, even light spot as you see in Figure 1a.

In Clinician’s Report May 2017 article,1 they compared the beam quality of different wireless lights. Most LED lights are not achromatic and produce uneven beams. (Figure 1b and Figure 1c)

Uneven beams often have bright central spots, which make it difficult to perceive the details throughout the entire beam area. Also, note that brightness is not equal to quality! An overly bright central spot will produce a great amount of glare, which is counterproductive to perceiving detail.

SurgiTel’s LED, featured in Figure 1a and Figure 2a, produces an effect like in Figure 3a. As you can see, our LED in Figure 3a is most like the normal room light in Figure 3b. In Figure 3a the contrast and detail are even greater than in Figure 3b, and definitely better than in Figure 3c.

This quality difference is due to SurgiTel’s achromatic beam technology.

Color Balance and Image Clarity

An important part of seeing your target is the contrast between colors. If your headlight emits nothing but a blue haze, there is no color contrast!

At SurgiTel we know that color accuracy is important for your work and have strived to make the color of our LEDs to best approach the color of natural sunlight. As you can see when comparing Figure 2a to Figure 2b, we have brought our LED exceedingly close.

Natural color is not only best for color accuracy and all cosmetic work, but is also much more comfortable to look upon. Have you ever looked into the cool white headlights of an oncoming car at night? Those tinted lights certainly appear bright, but are terribly uncomfortable to look upon.

Also, note the color temperature of SurgiTel’s achromatic beam stays constant as the working distance varies, but the color temperature of the non-achromatic beam varies as the working distance varies. If you were working with a non-achromatic beam, you might just find your target appearing differently colored as you move around your subject! The achromatic beam will provide the best color accuracy, no matter your positioning.

Blue Light Hazard and Eye Safety

Research published in the Journal of the Tennessee Dental Association has indicated blue LED lights, especially when magnified through loupes, may lead to health issues such as retinal damage and early-onset macular degeneration.4 Extreme blue light is what dental professionals protect themselves against by using protective lenses during curing procedures.

White LED lights actually consists of a blue spectral band and a green/red spectral band. White LED lights are available from neutral color (4,000K) to extremely cool colors (about 10,000K). At 4,000 Kelvin (K) the peak of the blue spectral band is similar to the peak of the green/red spectral band. As the Kelvin temperature increases, the blue spectral band becomes stronger. The Clinicians Report article shows SurgiTel lights at 4,000K and 3,900K. The SurgiTel neutral LED was the most color-balanced light tested (Figure 4).3

Vision and Ergonomics at Work

With SurgiTel’s achromatic beam technology, you can see better and work safer.

For more information, or to see them in person, contact your, local representative, at!



  1. “Cordless LED Headlamps: A Bright Idea?” Gordon J. Christensen Clinicians Report. CR Foundation, May 2017.
  2. Chang, Jin. “Fundamentals of Clinical Illumination and LED Technology.” SurgiTel. ErgoPractice News, November 2013.
  3. “Smaller and Lighter LED Headlamps.” Gordon J. Christensen Clinicians Report. CR Foundation, April 2012.
  4. Stamatacos, Catherine, and Janet L Harrison. “The Possible Ocular Hazards of LED Dental Illumination Applications.” The Journal of the Tennessee Dental Association 93, no. 2 (2013): 25–29.