Problems with Blue Light Disrupting Sleep
Recently I watched a show on The Nature of Things called “Lights Out”.
http://www.cbc.ca/natureofthings/episodes/lights-out
They were studying how certain wavelength of light emitted by light bulbs( the “blue” light in the 450-480 nm wavelength range) interfered with the human bodies natural sleep patterns. Some of the worst offenders are the new high efficiency LED bulbs available today, LED TV screens and also computer and smart phone screens. They recommend using special filter screens to block out the blue light wavelengths emitted from your devices and to use light bulbs that eliminate those disruptive blue light wavelengths.
I know for a lot of people designing high efficiency, low energy houses (either grid tied or off the grid)prefer using LED bulbs because they require the lowest amount of power but has anyone designed their lighting system to take into account the bulbs light spectrum?
There are some bulbs available now that omit these wavelengths but the remaining light is quite amber. Are there better choices?
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Replies
Scott,
As a "younger" guy that likes to look at screens most of the day, I've been made aware of and have strategies in place for blue light exposure.
However, you're right, home lighting is far from mimicking the natural human lighting that we've evovled with, (ie before electricity which is not that long ago).
But heres the rub, we can also use technology to our advantage as well. Blue light can really wake you up and get you more productive, especially in dark winter months. (I'm in zone 6)
Early in my current build I knew I wanted all LED downlights and researched exhaustively for temperature changing downlights, I believe currently they're mostly available in commercial applications and not much for resi. However, I plan to use lite line's "dim-to-warm" led downlights, where as you dim the lights it changes to a warmer temperature and eliminates most of the blue. So this gives me control in having lots of bright blue when I want it, and nice dim reddish as I'm winding down my day.
Next thing will be figuring out how the control the light circuits with an app to slowly sunrise all the lights in sync with my phones alarm clock, and to slowly sunset the lights as it's time to go to bed.
As somebody from the London, ON area with the Labatt Brewery in town, I thought this post was totally about something else. Usually, for me, the more Blue Light I have the easier it is to fall asleep ;)
FYI, Costco has a light fixture with a remote, motion sensor (with sensitivity), dimmer, timer, and the ability to change from warm to blue light, for a whopping $25. It's not smart in that you can't automate it, but I bought several for the new build. Couldn't find out if the remote is IR, but I may be able to hack it with an ir blaster of some sort if it is. Perfect for several locations in the house. Also had a night mode where it will decrease to 20% and warm light. I've also read about the blue light issue, so it is a concern for me as well.
I wouldn't lose sleep over it.
To clarify, the issue isn't that blue light is bad for you. Rather it's that your body's biological clock synchronized to the daily cycle at your location using sunlight exposure. Sunlight has more blue than many LED lights or screens, and getting sunlight exposure to get your clock running right is good for you. People at polar region have winter health problems because of inadequate exposure. The problem comes when you use bright artificial light in the evening and confuse your natural timekeeping function.
To avoid the problem of too much green/blue light in the evening, you can use any combination of turning off the screens and lights, simply dimming them, or shifting the color in the red direction. You can get software to do a color shift on computers and phones (f.lux is one I like), or you can add physical filters in front of screens. Similarly, you can have some designated evening lights in your house with very-low-color-temperature bulbs, or even pure red bulbs, or with filters. Or, you can do as Jamie B suggests and get "dim to warm" bulbs that shift the color in the red direction when you dim them. I just saw some of those on clearance at Home Depot for less than $2. My guess is that more bulbs and other LED lights with that feature will be available in the next year or two.
Note that the "quite amber" appearance of lights that omit blue/green wavelengths is an inherent and necessary result. There's no way do design around that fact that the same wavelengths that have that biological activity also make the light appear less amber. You simply have to accept that tradeoff. The nice thing about dim-to-warm is that you can make that transition gradually in the evening.