The Future of Light

The body clock is influenced by changes in light throughout the day. Photo by Den Heslop.

Edison’s commercialization of the electric light bulb quite literally changed the world. His technology helped enable the power grid, modern transportation, and ultimately the lifestyles we enjoy today. Lighting improved gradually over the last century until the recent mass adoption of LEDs.

As LED lighting goes mainstream, we face new challenges. You can no longer buy a 60 Watt bulb. Instead, you have to dive deep on CCT, CRI, lumens, and other jargon. There is an increased awareness of the risks of blue light coupled with unwarranted demonization of the new technology. The lighting industry as a whole faces stagnation.

How do we get out of this mess, and where do we go from here?

The LED Revolution

Red and green LEDs have been around for about 50 years, mostly confined to use as indicator lights in electronics. In the early 90s, three Japanese researchers at Nagoya University and Nichia Chemical created the first blue light emitting diode (LED) from gallium nitride (GaN).

One of the blue LED inventors, Shuji Nakamura. Photo by Ladislav Markuš.

The discovery by Nobel recipients Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura was significant because blue light can be converted to white light by means of a phosphor material. The phosphor material, for example yttrium aluminium garnet (YAG), is generally yellow in color and sits atop the LED die material.

In the mid-2000s, companies started packaging blue LEDs and phosphors into bulbs and other light sources. These early products were expensive ($20-$50 for a bulb) and largely had problems with color consistency, heat, and lifetime.

Today, you can buy an LED bulb for about $1.50.

The cost of components dropped, along with increases in performance. According to Haitz’s law, the cost per lumen (an amount of emitted light) decreases by a factor of 10 each decade.

Today, you can buy an LED bulb for about $1.50. That bulb has better color performance than its swirly compact fluorescent equivalent, and lasts 10,000–20,000 hours. Other LED sources can last significantly longer (50,000–100,000 hours). By contrast, an incandescent bulb may last 1,000–2,000 hours.

LED lamps are not far off in price from incandescent lamps at the point of sale. But their long lifetimes and low power usage mean you can save significantly more. Over the life of a cheap LED bulb, you will pay about $12, including the purchase price and energy. Five 60 Watt incandescent bulbs would cost about $78 over the same period of time. And don’t forget that you have to change the bulb five times instead of just once.

You probably wouldn’t know it, but this trendy Edison-style bulb is LED. Photo by IKEA.

Efforts have been made to phase out the sale of incandescent bulbs in numerous countries. Even though legislation has not passed in some places, the lighting industry has largely moved on to LED anyway. IKEA became the first large retailer to sell only LED lighting in 2015, and others are making similar moves.

The efforts are working. According to the U.S. Department of Energy, LED market penetration was 12.6% in 2016. That’s up from just 3% in 2014.

Massive Choice, Massive Confusion

All is not well. LED had its moment of differentiation, but now it’s largely a race to the bottom in price. That $1.50 bulb purchase will happen one-fifth as often, breaking old business models. The old stalwarts struggle to compete with new discount-oriented brands.

General Electric, the company Thomas Edison founded, plans to sell its bulb business due to low profit margins.

People just want their 60 Watt bulb back, energy savings be damned.

It’s not even all that great for consumers. That LED bulb is cheap, but you probably don’t really know what you’re getting. The Home Depot and other retail outlets don’t do a good job of explaining color temperature (CCT), lumens, and color rendering index (CRI). Manufacturers fuel the confusion with misleading terms like “soft white” and “bright white.”

Early LED products were plagued with reliability issues and ugly color, further contributing to the stigma.

Oh, you want to use that bulb with your existing dimmer? Forget about it.

All of this leads to mass dissatisfaction. And dissatisfaction results in returns, which does not help the already low-margin consumer lighting business. People just want their 60 Watt bulb back, energy savings be damned.

Things are a bit brighter in the commercial sector. LED fixtures are available in a million shapes, sizes, and colors. Energy and maintenance costs are drastically reduced, improving a building’s bottom line.

Most commercial LED fixtures have no lamps to replace. They are intended to last until the next renovation. Barring any electronics failures, LEDs don’t “burn out.” They just get dimmer over time.

The Lighting Facts label is now found on most lamps. But it is still not clear enough for the everyday user. Image by DOE.

But the B2B sector also has its issues. Lighting controls are increasingly requested, and in some cases even required by law. Very few manufacturers make all the components of a lighting system, leading to incompatibilities. Even when the stars align, it can be extremely costly and time-consuming to commission the system as intended.

The DLC standard focuses so much on energy efficiency that it may ultimately impair quality of light. California, historically the most progressive state in energy regulations, has fought back, putting a higher emphasis on color performance than energy. LEDs are efficient enough, they say. But the state is now under scrutiny for overriding federal energy efficiency regulations.

Blue Light Blues

At the same time, we have become aware of the effects of light on the human circadian rhythm. There’s debate about the nuances, but in general, you can sleep better and perform better when there is significant blue light during the day and very little at night.

In addition to the rods and cones, there is a third type of photoreceptor in our eyes that is only sensitive to blue light. Instead of contributing to vision, these cells tell the body clock when it is daytime and when it is not.

This mechanism worked well up until the last 150 years or so, before electric lighting became ubiquitous. The same lighting found in our homes and electronic devices can trick the body clock into thinking it’s daytime when it is really not.

It’s not like the issue is limited to academics. People are aware of the effects of blue light, and want solutions.

Circadian rhythm disruption may seem like a first world problem, less important than public health issues related to malnutrition and poverty. But it has been linked to breast cancer, Alzheimer’s disease, and other conditions. Additionally, shift work and frequent time zone hopping can contribute to accidents on and off the job, as well as inconsistent menstrual cycles in females.

Apple is the only household name to have taken a significant stance on this problem, with the introduction of Night Shift on iOS in early 2016 and on MacOS in 2017. Night Shift changes phone and computer screens to an orange hue at night, reducing the blue light content. Even then, the feature is not enabled by default and not widely advertised by the company.

Anecdotally, I was in an Apple Store recently. A little old lady came up to one of the employees and asked how to get the orange light back on her phone. It’s not like the issue is limited to academics. People are aware of the effects of blue light, and want solutions.

Usage of blue-light emitting displays at night can disturb the body clock. Photo by KristopherK.

The lighting industry, in general, has made little progress in providing straightforward products that address circadian disruption. The specification community, which includes lighting designers and architects, is begging for systems that support their latest human-centric designs. But their pleas mostly fall on deaf ears.

The industry’s arguments du jour against human-centric lighting circle around: not enough research, disagreements on the spectrum of light, and complexity of integrated systems. In my opinion, these are excuses to avoid pioneering in an unverified market.

The lighting giants are blind to the potential of human-centric lighting to differentiate their businesses. There is room for someone to come in and make a big splash.

Circadian Lighting

Several upstarts have created a category that I call circadian lighting. Broadly speaking, circadian lighting shifts in color and brightness automatically throughout the day. The morning begins with a warm, dim glow, giving way to cool, bright light during working hours. In the evening, the lighting shifts back to a warm glow. It’s a lot like f.lux and Night Shift, but for your environment.

One of the most notable startups in this category is Ketra, which makes a circadian lighting system that can be installed in the home and commercial environments. It’s not particularly affordable, but the Ketra system is the most complete and ready-to-go out of the box circadian lighting solution at the moment.

Not only does circadian lighting match the science, but it also just feels right. Cool, relatively bright lighting during the day makes the indoor environment seem more like outside. In the evening, dimmer, warmer light promotes relaxation. Waking up in the middle of the night, only very dim light is needed to guide the way. Otherwise, the light would startle.

Honeybrains, a health-focused fast casual restaurant in New York City, featuring circadian lighting by Ketra.

Ketra’s offering is by far the most impressive, but there are signs of light from other manufacturers. Philips offers an LED bulb for about $6 that can change between three color settings (dim and warm at night, normal bright incandescent, and cool, bright white for the day) simply by flicking a switch. IKEA has something similar but with wireless remote controls and dimming for $27.

These products can only be controlled manually, and thus are not true circadian lighting. But they are something you can buy today for not a lot of money to get a glimpse into the future.

Light Tuned to You

Circadian lighting sounds great, but what about all the other factors that can influence the circadian rhythm? What about food, social events, caffeine, alcohol, stress, and travel?

A lighting system is unlikely to counteract circadian disruption completely. However, if it knows about your circadian state, the lighting could help normalize the body’s cycle of sleep and wake.

The lighting in your environment would always be the right light for you.

Let’s say you’re traveling to Tokyo in a week. Your destination is 13 hours ahead of Eastern Daylight Time. Instead of throwing your circadian rhythm into a complete 180 upon arrival, circadian lighting could help you shift to the new time zone in the days leading up.

Or you’re a shift worker on the night shift. But you also have weekend activities planned with your family, most of which take place during the day. Circadian lighting could help reduce the grogginess associated with rapidly changing sleep patterns.

Circadian lighting could reduce the symptoms of jet lag. Photo by Jon Tyson.

What if the lighting in your home, car, office, and gym was tuned to your circadian rhythm? What if the light at your desk was different from the light at your neighbor’s desk? What about the lighting in your airplane seat and the hotel room or Airbnb thousands of miles away?

What if the lighting system knows not only that someone is present in a room, but also who that happens to be? The lighting in your environment would always be the right light for you. You never would have to do much more than dim the lights, and maybe not even that.

Building the Killer App

LED lighting quickly moved from an expensive toy for early adopters to a cheap commodity. Now there is room for a killer app, and I believe advanced, connected circadian lighting is the answer.

A great product is simple, understandable, and affordable.

The pieces of the puzzle already exist to make all of this happen. A combination of GPS and an indoor positioning system can pinpoint your precise location anywhere in the world. Info about your sleep hygiene could come from a Fitbit or smartwatch. A phase response curve would be applied to shift your circadian rhythm by the amount appropriate at any given time.

Estimote sells an indoor positioning system solution that could be integrated with lighting.

Whoever builds a circadian lighting solution will recognize that it is no easy feat. It takes an understanding that a great product is simple, understandable, and affordable. It takes the right people working toward a uniform, opinionated vision.

We’ve seen the potential of circadian lighting to positively impact people’s lives. The awareness is there, and will continue to grow.

Now we’re just waiting for the right solution.

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