Category: Research

The Fairmont Press Publishes Lighting Redesign for Existing Buildings by LightNOW Editor Craig DiLouie

I’m pleased to announce that I have finally completed the long awaited (by my publisher) update to The Lighting Management Handbook, which came out in 1994, with this 300-page book…

I’m pleased to announce that I have finally completed the long awaited (by my publisher) update to The Lighting Management Handbook, which came out in 1994, with this 300-page book about redesigning existing lighting systems: Lighting Redesign for Existing Buildings.

Because light is used to see but cannot be seen, it is often overlooked by its users. The presence of light is rarely noted, in fact, unless there is a perceived lack of it (dim atmosphere or shadows) or a perceived excess (glare). Like air, however, light is invisible and yet everywhere in the visual environment, as we cannot see without it. And seeing, in turn, is fundamental to economic and leisure activity for the large majority of the population who are sighted. Like electricity and clean water, light is an engine of progress.

Ubiquitous in the built environment, light is generally considered a commodity, and the main economic consideration is how to obtain it more cheaply. For this reason, educated owners of new and existing buildings are finding it highly profitable to invest in energy-efficient equipment to reduce lighting energy costs by as much as 50 percent or more. These projects often take the form of simple lamp and ballast replacements.

These investments can be a great uses of capital. They can also be a waste of money, even if the project achieves an excellent financial return based on lower operating costs. The reason is simple: Light is for people, not buildings. Decisions about light may be all about dollars and cents, but dollars and cents are not all about energy.

In short, it is not enough for light to be energy-efficient. It must also be effective. What does it mean for a lighting system to be energy-effective?

First, we must understand that the application of light is lighting—not only the equipment that acts as the delivery system for light, but also where the equipment places light and with what direction, intensity and color. As people respond to varying levels of brightness and color in the field of view, light can be applied to the same space to impact a building and its occupants in different ways. While light makes sight, lighting is about perception—whether a space appears tense or uninteresting, public or private, spacious or intimate, productive or relaxing, and so on. Some 80 percent of sighted people’s impressions of the world, in fact, are generated by what they perceive with their eyes. This is where lighting delivers tangible economic benefits beyond simple vision. Properly applied, lighting can produce higher sales of key merchandise, optimize the productivity of office workers, offer a memorable experience for visitors, beautify space and architecture, improve learning rates, influence human interaction and mood and atmosphere, and promote safety and security.

It should be noted that bad lighting can realize opposite effects.

Given the benefits of good lighting design, and the high economic stakes involved, we may be thinking about light all wrong. Yes, light is a commodity. But lighting is a business asset—a critical asset of both the built environment and the organization that occupies it.

In existing buildings, this asset is often neglected. According to the Department of Energy, while lighting upgrades are a popular renovation investment, lighting upgrades have been performed in only 29 percent of commercial building floorspace built before 1980. This suggests that about 25 billion sq.ft. of floorspace is still lighted to pre-1980 standard using T12 lamps, magnetic ballasts and overlighted spaces.

Upgrading these lighting systems to today’s lighting efficiency standards could generate lighting energy cost savings of up to 50 percent or more. As the fluorescent magnetic ballast becomes virtually eliminated in 2010 and the fluorescent T12 lamp with it in 2012, building owners should begin exploring opportunities to convert their lighting systems to more-efficient technologies in a way that achieves maximum benefit. But focusing solely on how much energy a lighting system uses is like buying a forklift based solely on its fuel efficiency instead of how much it can lift, how it handles, its speed, safety features and so on. After all, the purpose of lighting is not to draw wattage, but instead, depending on its application, to enhance task performance, provide visual comfort, reveal form and architecture, attract interest and so on. In short, lighting should be effective as well as efficient.

Here, too, research suggests that the lighting asset is often neglected in buildings in terms of lighting quality, perpetuating lighting systems that may have been poorly designed or designed to outdated standards, and poorly maintained since then. According to a 1999 office lighting survey conducted by office systems manufacturer Steelcase, 37 percent of workers said the lighting in their workspace was either too dim (22 percent) or too bright (15 percent), while three out of four said they wanted more control over light levels. Further, three out of four office workers said better lighting would improve their efficiency and productivity, while two out of three said they would be more creative.

This means simple replacement of lamps, ballasts and controls is not enough. A component-based retrofit approach may save energy, but perpetuate a poor design that fails to achieve the business goals of the organization that invested in owning the asset and wants to realize its value. Instead, the lighting system may need not retrofit, but relighting—a redesign that addresses effectiveness as well as energy performance, including issues such as visual comfort, uniformity, color rendering and light on walls and ceilings. Because it is not enough for a lighting design to be efficient; it also has to shine.

Some of these issues run deep, and can be challenging to address properly at very low levels of energy consumption. As complexity increases due to advancing lighting technologies and an imperative to optimize lighting quality as well as energy efficiency, so has demand for greater expertise from designers of lighting systems.

Lighting Redesign for Existing Buildings was written to educate owners, energy managers, electrical engineers, architects, lighting designers, consultants, electrical contractors, electrical distributors and other interested professionals about the relighting of existing buildings. The information may apply to lighting design in new construction as well. Its thinking transcends my first book about lighting upgrades, The Lighting Management Handbook, published by The Fairmont Press more than 15 years ago, challenging owners and designers to optimize lighting quality hand in hand with efficiency in existing buildings—and get the full value of an asset that is effective as well as efficient.

Click here for more information about Lighting Redesign for Existing Buildings.

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NLPIP Publishes Addendum to Report on Streetlighting Technologies

In September, the National Lighting Product Information Program (NLPIP) at Rensselaer Polytechnic Institute’s Lighting Research Center (LRC) released a publication called Specifier Reports: Streetlights for Collector Roads, which provides objective…

In September, the National Lighting Product Information Program (NLPIP) at Rensselaer Polytechnic Institute’s Lighting Research Center (LRC) released a publication called Specifier Reports: Streetlights for Collector Roads, which provides objective performance information on street lighting technologies including HPS, induction, LED, and pulse start metal halide (PSMH). The streetlights selected for evaluation were recommended in 2009 by nine different manufacturer representatives as equivalent to the incumbent 150W HPS streetlight.

The report concluded that the LED streetlights recommended by the manufacturer representatives as replacements for the incumbent streetlight would cost more than twice as much to own and operate over the life of the streetlights, primarily because the LED streetlights required narrower pole spacings to meet the recommended practice for illuminating collector roads, and the cost of the poles per mile dominated the life cycle costs.

Recent comments

NLPIP received some critical comments from government representatives who claimed that NLPIP made an error in the report by selecting “underpowered” luminaires to be equals to existing fixtures, even though “higher-powered” models might be available.

“The fact is that NLPIP’s methodology has been seriously misrepresented. The methodology emulated the luminaire selection process used by many lighting specifiers, which means that the luminaries analyzed by NLPIP were those actually recommended by manufacturer representatives as equivalent to an incumbent technology, a 150W HPS luminaire with a Type III distribution,” said LRC Director Mark Rea, Ph.D. “It is disappointing that all six of the LED manufacturer representatives recommended streetlights with lower light output than the incumbent technology, but, hopefully, the report underscores for specifiers the problems associated with blindly accepting all the current claims surrounding solid-state lighting. That should be the focus of discussion among those in the industry.”

Analysis with “high powered” LED streetlights
To minimize misinformation, NLPIP added an addendum to Specifier Reports: Streetlights for Collector Roads. The addendum is an analysis of “higher-powered” LED streetlights that NLPIP identified from the websites of the LED streetlight manufacturers included in the main report. NLPIP investigated LED streetlights with enough light output to meet lighting criteria as defined in the American National Standard Practice for Roadway Lighting, ANSI/IESNA RP-8-00 (R2005) at the same pole spacing as typical HPS streetlights. Because poles dominate the total life cycle costs of roadway lighting systems, the pole spacing was held constant for this analysis. Current (October–November 2010) LED streetlight prices and manufacturer-provided photometric data were used.

The results indicate that the average relative life cycle cost (excluding pole costs) for the LED streetlights would be 2.3 times the average relative life cycle cost of the 150W HPS streetlights if the LED modules were to require replacement after 25,000 hours of operation. An LED module life of 50,000 hours would result in the LED streetlights having an average relative life cycle cost 1.7 times that of the 150W HPS streetlights.

These results are based on a comparison between lighting technologies, using a technology-neutral methodology, according to NLPIP.

“We encourage specifiers to actually read Specifier Reports: Streetlights for Collector Roads and draw their own conclusions, rather than relying on faulty interpretations posted on blogs or distributed via mass emails,” said Rea. “There is no doubt that LED luminaires will play a strong role in the future of lighting. NLPIP is simply raising awareness of the strengths and weaknesses of current technologies and products in order to help specifiers make informed decisions. NLPIP has contributed to the industry in this way for 20 years by providing access to objective, verifiable, research-based data.”

Click here for NLPIP’s response to comments made about the report.

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Jim Brodrick on Round 11 of CALiPER SSL Product Testing

Guest post by Jim Brodrick, U.S. Department of Energy t’s been a while since I’ve written about DOE’s CALiPER testing program, and the Round 11 Summary Report was published this…

Guest post by Jim Brodrick, U.S. Department of Energy

t’s been a while since I’ve written about DOE’s CALiPER testing program, and the Round 11 Summary Report was published this week. As always, the results are worth noting. For those of you who don’t know, CALiPER tests a wide range of solid-state lighting products that are available on the market, and for benchmark purposes compares them with similar products that use traditional light sources. The results of each round of testing are highlighted in a Summary Report, with detailed reports going into greater depth.

CALiPER Round 11 was conducted from March to September of this year and looked at 31 LED lighting products in five applications: arm-mounted roadway luminaires, post-top roadway luminaires, linear replacement lamps, high-bay luminaires, and small replacement lamps. Overall, there were some encouraging findings. For example, we saw a continuation of the steady increase in average overall efficacy over previous rounds. And although many products continue to carry misleading equivalency claims and inaccurate performance metrics, performance claims for a number of products were found to be accurate – especially for those products carrying the Lighting Facts® label.

Regarding LED linear replacement lamps, there’s good news and bad news from Round 11. The good news is that they’re getting better, especially in terms of efficacy – but the bad news is that they still have some major performance issues in the areas of light distribution, color quality, and reliability. Still, using a troffer equipped with two SSL lamps to replace a single-lamp fluorescent troffer in situations where lower light levels are needed, or where other SSL characteristics provide an advantage, may now be viable in some cases – even though at this point in time LED linear replacement lamps will probably not be the most cost-effective or reliable option.

There’s been a lot of interest lately in outdoor applications for SSL, which makes the Round 11 roadway luminaire findings especially timely. Those findings were a mixed bag. Both the arm-mounted and the post-top luminaires showed a wide range in performance, although there was significant improvement on average over earlier rounds. Half of the SSL outdoor luminaires achieved light output and efficacy levels that matched or exceeded those of their benchmark counterparts, but most of those tested exhibited substantial variations in color characteristics (either CCT, Duv, or both) as compared to their rated CCT.

Five out of the six arm-mounted roadway LED luminaires tested met or came close (within 10%) to meeting manufacturer ratings for expected light output and efficacy. But both types of outdoor luminaires showed a broad range of distribution characteristics, which would require close analysis to determine their adequacy for a given application. While some of the LED products claim equivalency to 100W HPS, that equivalency may only be valid in a limited number of installation scenarios. In other words, depending on the particulars of a site, these LED products may or may not be suitable for that site.

So what’s the take-home message here about outdoor lighting, based on CALiPER Round 11? That evaluating it is not a simple matter. There are a lot of subtleties that come into play and have to be taken into consideration, which means that potential users need to look closely at the specific application, to see whether a product is suitable or not.

There’s a huge range in the performance of these LED products. Many wouldn’t make suitable one-for-one replacements when used with existing street-lighting systems, but might make economic sense with new installations. Why? Whether seeking to replace existing luminaires with LED or some other technology, the replacement product will always be faced with the challenge of competing in an application that was likely optimized around the existing product. Pole spacing may be somewhat flexible in new installations, thereby offering opportunities to optimize the installation for LEDs.

So when evaluating LED lighting products, there’s really no substitute for looking carefully at the requirements of each application and looking at photometric data obtained from standardized testing for each product being considered. And that holds true not just for roadway lighting, but pretty much across the board. Doing that can expand the options, while minimizing the likelihood of making a decision that will later be regretted.

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DOE Releases Summary Results from Round 11 of CALiPER Testing

The U.S. Department of Energy has completed Round 11 of product testing through the its CALiPER SSL program. Round 11 included five primary focus areas: * roadway arm-mount luminaires *…

The U.S. Department of Energy has completed Round 11 of product testing through the its CALiPER SSL program.

Round 11 included five primary focus areas:

* roadway arm-mount luminaires
* roadway post-top luminaires
* linear replacement lamps
* high-bay luminaires
* small replacement lamps (MR16, PAR lamps, A-lamps, and a candelabra lamp)

As a benchmark, traditional lighting products using incandescent, halogen, fluorescent, high pressure sodium, pulse-start metal halide and ceramic metal halide light sources were also tested and included in
a summary report available here.

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Jim Brodrick on the Lighting Research Center’s Report on Streetlighting

Guest post by Jim Brodrick, U.S. Department of Energy Some of you may have seen a new report on street lighting by the Lighting Research Center (LRC) at Rensselaer Polytechnic…

Guest post by Jim Brodrick, U.S. Department of Energy

Some of you may have seen a new report on street lighting by the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute. A number of people have asked for my comments on that report, so here goes.

In a nutshell, the LRC report implies that GATEWAY reports are potentially misleading, and describes an in-house study – conducted by the LRC’s National Lighting Product Information Program (NLPIP) – that found LED street lighting to be vastly inferior to high-pressure sodium (HPS) and pulse-start metal halide (PSMH) fixtures for collector roads (roads that connect local streets with arterials). A corollary implication of comments LRC published in association with the report is that DOE is biased in favor of SSL at the expense of other lighting technologies, and is blindly pushing it without regard to its suitability.

As I’ve mentioned before, GATEWAY focuses on LED products for a very good reason: GATEWAY is part of DOE’s solid-state lighting program, and DOE was specifically directed by Congress to support the development, improvement, and deployment of SSL technology. Why? Because no other existing lighting technology has as much potential to save energy and improve lighting service over the next 20 years. But that doesn’t mean DOE has tunnel vision when it comes to solid-state lighting. On the contrary, DOE has other programs that promote efficient conventional lighting technologies, such as the Commercial Lighting Solutions program and the Commercial Building Energy Alliances.

And just as important, as anyone who reads these Postings knows, DOE’s solid-state lighting program regularly publishes materials critical of a wide range of LED products on the market and urging caution in product selection. See, for example, the CALiPER testing summaries, numerous presentations urging potential buyers of LED products to be very careful in product selection, and most recently, Municipal Solid-State Street Lighting Consortium guidance which states that “the surest way to reduce risk, while simplifying the process of luminaire selection and lighting design, is to enlist the help of a qualified lighting professional.” That doesn’t sound like DOE urging a headlong rush into LED products.

The purpose of GATEWAY is to document real-world experience with LED lighting products in the field. This is critical because even with well-designed products, many problems and performance issues are not apparent until the products are installed. GATEWAY installations will also yield important information over time about lumen maintenance, reliability, maintenance costs, and energy savings. As a new technology, SSL lacks this long-term track record. Conventional lighting technologies already have a track record, and thus are less in need of an intensive government effort to document their performance.

What’s more, GATEWAY was created to evaluate LED products based on the parameters of the host site, and an extensive pre-investigation is always conducted before the actual demonstration begins, in order to determine the feasibility of using SSL. If DOE determines that conventional technology products are clearly more suitable for the application, then no GATEWAY demonstration takes place at that site – we advise the owner that we don’t think LED products are a good investment for the site at this time, and move on.

As for the LRC study, a critical error was committed at the outset which affects all of its conclusions. Although I’m sure it wasn’t intentional, LRC selected some woefully underpowered LED products to compare with HPS street lamps, and then concluded that LED products aren’t competitive because of the high cost of having to purchase additional luminaires and poles to make up for the insufficient light. That’s kind of like racing a Ford Pinto against a Chevy Corvette and then concluding that all Chevys are faster than all Fords.

There are plenty of higher-powered LED products on the market that are appropriate for the study application, and selecting them would have resulted in higher luminaire output, thereby providing a fair comparison with the HPS products that were selected. This fundamental flaw in methodology completely undermines the LRC’s general statements about LED performance. The conclusions that LED systems need more luminaires and poles, and therefore have significantly higher first costs, are a direct result of this critical error in product selection, and consequently are baseless.

The LRC published several other reasons for why they think GATEWAY reports are misleading, but these don’t hold water either. For example, the LRC criticizes GATEWAY for basing our economic analyses on existing pole spacing, but changing pole spacing at test sites would often be exorbitantly expensive, not to mention disruptive to the site’s business. And LRC criticizes GATEWAY for a study in which illumination levels were cut in half by the new SSL luminaires, accusing GATEWAY of attributing the resulting energy savings to SSL – when in fact the report for that GATEWAY study contains a very clear caveat urging readers not to attribute the energy savings to the new technology, and makes clear in its conclusions that the energy savings were due to reducing illumination levels at an over-lit location.

In general, the LRC’s comments on DOE’s GATEWAY program underscore the difficulty of comparing the economic and energy performance of systems in the field, where – unlike laboratory or computer simulations – all other factors can’t be held constant. That’s precisely why we’re so careful not to draw generalized conclusions based on each GATEWAY report, and why each report always plainly states that the economics and energy performance it contains are based only on that particular site and the particular products analyzed.

In fact, as most of you know, the importance of doing due diligence on specific products, including confirming that those products are suitable for the application in question, is emphasized by DOE throughout its SSL presentations and published materials. LRC’s approach of simply taking products selected by distributors “as is,” without independently confirming that the selected models were actually suitable for their simulated test site, serves as an excellent illustration of the incorrect conclusions that can result from trying to apply unsuitable luminaires to a site.

Although the LRC’s intentions were good, the results of their study are seriously flawed. Street lighting is one of the applications for which SSL clearly is already competitive with incumbent technologies, as GATEWAY has shown and numerous members of DOE’s Municipal Solid-State Street Lighting Consortium – who have investigated LED products on their own – will attest. That doesn’t mean every LED street lighting product is a good one, or that SSL is the right choice in every street lighting application. But it does mean that SSL should be in the running for street-lighting applications when saving energy and money are important considerations.

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New Report on Street Lighting Technologies Available From The Lighting Research Center

The National Lighting Product Information Program (NLPIP), based at the Lighting Research Center in Troy, NY, recently released its latest Specifier Report, designed to provide objective performance information on existing…

The National Lighting Product Information Program (NLPIP), based at the Lighting Research Center in Troy, NY, recently released its latest Specifier Report, designed to provide objective performance information on existing street lighting technologies includingLED, induction, and high pressure sodium streetlights.

NLPIP performed photomet­ric evaluations of 14 streetlights that used either HPS, pulse-start metal halide (PSMH) or induction lamps, or LED modules. NLPIP analyzed the streetlights for light output and distribution, energy use, spectral effects on visual performance, discomfort glare, and economic factors. The streetlights were evaluated as part of installations that meet the lighting criteria as defined in the American National Standard Practice for Roadway Lighting, ANSI/ IESNA RP-8-00 (R2005), for a simulated one-mile stretch of collector roadway (a road servicing traffic between local and major roadways).

According to NLPIP, when replacing the pole-mounted HPS streetlights on a one-mile section of collector road with the LED or induction streetlights used in the study, it would take twice as many of the pole-mounted LED or induction streetlights to meet the lighting criteria as defined in RP-8-00.

Complete performance results are published in Specifier Reports: Streetlights for Collector Roads, which is available online here.

“The LED and induction streetlights we tested required narrower pole spacing. As a result, the life cycle cost per mile was dominated by the installation cost of the poles, as opposed to the initial cost of the streetlights or any potential energy or maintenance cost savings, as one may assume,” says Leora Radetsky, LRC lead research specialist, principal investigator and author of the report.

LED and induction technologies are often marketed as money saving alternatives to HPS, with some manufacturers claiming reductions in energy and main­tenance costs. However, NLPIP found that the HPS and PSMH streetlights evaluated in this test provided a better cost value than the LED and induction streetlights evaluated, which would need to produce about the same street-side lumens as the HPS models to be economically competitive.

The average power demand of the LED streetlight layouts evaluated was slightly lower than the average power demand of the HPS streetlight layouts, but there was wide variation among LED models, according to NLPIP.

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Controls Friday: Typical Energy Savings for Using Advanced Lighting Controls

How much energy is saved when a building uses lighting controls? The typical answer is the ever-present lighting term, “It depends.” Research, however, is suggestive: Space Type Controls Type Lighting…

How much energy is saved when a building uses lighting controls? The typical answer is the ever-present lighting term, “It depends.” Research, however, is suggestive:

Space Type Controls Type Lighting Energy Savings Demonstrated in Research or Estimated as Potential

Study Reference

Private Office Occupancy sensor 38% An Analysis of the Energy and Cost Savings Potential of Occupancy Sensors for Commercial Lighting Systems, Lighting Research Center/EPA, August 2000.
Multilevel switching 22% Lighting Controls Effectiveness Assessment, ADM Associates for Heschong Mahone Group, May 2002.
Manual dimming 6-9% Occupant Use of Manual Lighting Controls in Private Offices, IESNA Paper #34, Lighting Research Center.
Daylight harvesting (sidelighting) 50% (manual blinds) to 70% (optimally used manual blinds or automatic shading system) “Effect of interior design on the daylight availability in open plan offices”, by Reinhart, CF, National Research Council of Canada, Internal Report NRCC-45374, 2002.
Open Office Occupancy sensors 35% National Research Council study on integrated lighting controls in open office, 2007.
Multilevel switching 16% Lighting Controls Effectiveness Assessment, ADM Associates for Heschong Mahone Group, May 2002.
Daylight harvesting (sidelighting 40% “Effect of interior design on the daylight availability in open plan offices”, by Reinhart, CF, National Research Council of Canada, Internal Report NRCC-45374, 2002.
Personal dimming control 11% National Research Council study on integrated lighting controls in open office, 2007.
Classroom Occupancy sensor 55% An Analysis of the Energy and Cost Savings Potential of Occupancy Sensors for Commercial Lighting Systems, Lighting Research Center/EPA, August 2000.
Multilevel switching 8% Lighting Controls Effectiveness Assessment, ADM Associates for Heschong Mahone Group, May 2002.
Daylight harvesting (sidelighting) 50% Sidelighting Photocontrols Field Study, Heschong Mahone Group, 2003.

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IES Publishes Position Statement on Effects of Exterior Lighting on Human Health

The Illuminating Engineering Society has published PS-03-10, a position statement covering “Effects of Exterior Lighting on Human Health.” The statement includes the following salient points: “TM-18 represents the position of…

The Illuminating Engineering Society has published PS-03-10, a position statement covering “Effects of Exterior Lighting on Human Health.”

The statement includes the following salient points:

“TM-18 represents the position of the IES on the known relationships between optical radiation and human health.”

“The position of the IES is that typical exposures to exterior lighting after sunset have not been shown to lead to cancer or other life-threatening conditions.”

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Cleantech Approach Offers Free Report on Advanced Lighting Controls for Office Buildings

Cleantech Approach (CTA) has published a new research report: Lighting Controls: Savings, Solutions, Payback, and Vendor Profiles, reviewing lighting control solutions and ROI associated their deployment. The report finds that…

Cleantech Approach (CTA) has published a new research report: Lighting Controls: Savings, Solutions, Payback, and Vendor Profiles, reviewing lighting control solutions and ROI associated their deployment.

The report finds that commercial offices can reduce electricity consumption by 35-55% with the implementation of a lighting control solution and deliver an ROI within 2-10 years, depending on solution deployed.

Click here to download the report free.

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Researchers Study Light’s Medical Uses

The Wall Street Journal also reported today that light is increasingly being used to diagnose and monitor diseases such as diabetes, highly desirable because it is non-invasive. Light is already…

The Wall Street Journal also reported today that light is increasingly being used to diagnose and monitor diseases such as diabetes, highly desirable because it is non-invasive. Light is already used for eye surgery, dental work, cosmetic skin work, combating SAD, hair transplantation and other uses. Get the story here.

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