What's the best light for seasonal affective disorder?

A friend got a full spectrum bulb for around $40 the other day and figured it was a good deal. He said they’re good for treating Seasonal affective disorder, which isn’t that uncommon around here, but most people just eat more vitamin D for it. Looking into SAD a bit more wiki talks about light therapy for it as follows:

I know LEDs are narrow spectrum, and I’ve heard of some with a greenish tint but now I’m wondering if there are any intentionally at the 500nm wavelength.

Edit: Changed title from looking for 500nm drop in to what’s the greenest light.

You can get pure green LEDs - and cyan ones too. Unfortunately from a quick rake through Cree’s datasheets, they seem to have a gap between 485 and 520nm in most of their ranges of LEDs.

Here you go…

http://www.ledtech.de can probably sort you out. Oops - thought you were a Brit.

Send a PM to The_LED_Museum over on http://flashlightnews.net/ - he’s a nice guy and knows more about LEDs than just about anyone.

I have this thing in transit and it has red, white, and green lights of all things. I’ll let you know if it helps to cure my everyday disorders no matter what season it is. OTOH I may get a seizure or two out of it apparently. I can’t wait.
X-mas is almost here and I’m planning to light up every tree in the freakin’ neighborhood with it too.

That’s exactly what I’m looking for, thanks! Now the hunt for somewhere that stocks those, cause I don’t think I’ll order a full reel of 1000…

I’ve been following this issue for a very long time; what I’ve found useful, I’ve posted in comments at a science writer’s thread.
If you’re patient catching up, you can read that with many links (some still good, you know about bit rot) — look here:

That includes links to spectra of a wide variety of LEDs (thanks to LEDMuseum)

Aside — please contribute something to him if you use his site, it’s a wonderful, longstanding effort by one uniquely quirky guy, respected since the Internet was mostly Usenet (all text) long before the WWW).

He has a spectrometer and will show you what’s in the light.
I’ve sent him several light sources he’s included in those he posts. Link into his site for spectra: ledmuseum spectra - Google Search

Short answer: long ago, marketers suggested “broad spectrum” was needed to help winter blues; research found ordinary cool white office fluorescents worked fine. Some quack marketers still hype expensive ‘broad spectrum’ light sources — not needed.

Further research identified the effect as mediated by a newly discovered photoreceptor — sensitive only to the blue-green range, below 500 nm. That happens to be the biggest ouput peak for “white” fluorescents and LEDs — which emit high energy blue internally to excite the layer of phosphor. The phosphor re-emits the energy over a wide range we see as a warmer ‘color temperature’ — but the blue comes through. For evening use, you can filter it out with something like theatrical gel sheets or blue-blocker glasses)

Turns out more than just sleep cycles are controlled by this receptor system. We start getting sleepy a few hours after the sun goes down, without artificial light. But artificial light is also showing up as affecting other health issues.

See the recent American Medical Association statement on that.

Sounds like a cool guy to know. I tried to register over at the flashlight news, but it seems registration is currently disabled. I guess I’ll stick to lurking over there for now.

That’s some interesting info on the effects of artificial lights on photo-receptors. I’ll have to do more research into how that is wired into the nervous system.

PS, you might consider changing the title to “winter blues” or “seasonal affective disorder” if that’s your main interest for this thread.

I thought “greenest” would tell me which company makes LEDs with less waste and less landfill! (I’m looking for the Subaru of flashlights — no-landfill production)

Also for winter blues — if I could have only one tool, it’d be a dawn simulator set for the time the sun comes up in mid-August — about 6:30am. Combining that with using ordinary fluorescents up til 8pm (and no-blue-lights everywhere after 8pm) sets my day length at a bit over 12 hours of “daylight” and helps greatly to reduce the slide into winter depression. Start early if it’s an issue.
I’ve bought a variety of them over the years; this source makes several that are reliable and affordable:
http://windhovermfg.com/ (formerly found at URLs including sunraintime.com and humboldt1.com/~zerdo — noting that for search engines to turn up the new URL which is kind of hard to find)

A good summary on timing here: Seasonal Affective Disorder - The Basics | ScienceBlogs

take more vitamin D. Take 8000 IU, yes 8000, not your Gov. recommended 400 IU. Get it now, it’s cheap, before prices for D shoot up.

just passing along what I have researched and trying to help….

Does anyone know where to get a dawn simulator with radio and projection clock? Preferably budget priced. :slight_smile:

I have been trying to find them from Finland, but haven’t found one yet.

Another interesting treatment for winter blues is described here: http://www.valkee.com/uk/science.html#navigation (one of my work mates is using them and says that they really help - haven’t tried them myself as they are very expensive…)

> with radio and projection clock
Seems counterproductive to me; if set early the radio would wake me up before the dawn sequence had run (the nice thing about a dawn simulator is it works through closed eyelids and stops your brain from making melatonin; after that level drops you wake up).

If I used one I’d put a clock radio and projection clock alongside and set them for the time you want to be awake, after the dawn sequence is up to full brightness? (and a sheet of yellow filter over the projection light, see the Rosco theatrical filter gels I mentioned at the lignt/dark link).

> valkee
Interesting idea — LEDs in the ear canals, it’d work the same way as daylight that does get through skin and thin bone. I guess Solitaires would be about right :slight_smile:

> Vitamin D
Some info, but read the studies: http://scholar.google.com/scholar?as_ylo=2012&q=“vitamin+D”+“winter+depression”

Most of them have a radio, which automatically turns on after the dawn sequence. (makes sure I will wake up)

Not sure about solitaires, but a king on both sides of your head should be enough… :wink:

I indeed like my ‘dawn alarm clock’ which starts with a gradually increasing light and at full brightness starts to play a selected ‘nature’ sound. Which is not as annoying as a song you might hate or a commercial. That makes my wake up nice in winter.

For the ‘winter blues’ I’d suggest strong lighting with some blue component. Nothing fancy wavelength wise, as long as it is bright and overhead. My current room light is 10 meters of LED strip, 2700K CCT, of the 72 watt/5 meter variety. Ebay them. I had to turn down the voltage a bit because it was way too bright for my room (and ran too hot as well). I think a similar with LEDs in the 5000 - 7000 K range would work fine for simulating sunlight.

Remember it’s two kinds of light that are best for winter blues — each in the right part of a 24-hour cycle with the day length set for you
plenty bright light with the blue-green for your ‘daytime’ hours, and
switching to light without that band for your ‘evening’ hours
— the latter part takes more effort, as most artificial light nowadays has some of the blue-green (any white fluorescent or white LED)

Day length — there’s a good self-assesment at CET.org’s page.
How much of a lark or owl are you, compared with other people? When does your
internal clock think you should be going to sleep? If you are taking light
therapy, what would be the most effective time of day?

New tool for finding out what’s emitted, a kit spectrometer

SpectralWorkbench (“BLF Mini” white LED flashlight)
SpectralWorkbench (Arc AAA red-orange LED flashlight)
SpectralWorkbench (Macbook Pro white LED backlight)

More to come.

Spectral Workbench is part of Public Lab www.publiclab.org

I felt lazy and interested in what’s coming out of my various white LEDs (not to mention the bright white LED streetlights going in down the block)
so I paid $40 for their simple kit — it’s a board camera and cable with a USB plug, with a case (electrical hardware box), a light shield (cut-and-fold) with optical slit already cut for position, a piece of DVD (break off the colored part; the “transparent” layer has the fine lines, close enough to parallel out at the edge, to make a rainbow from a point source). Plus some tape and a wood block for getting the angle right. This is for making transmission spectra, so the camera focuses through the plastic, rather than looking at the rainbow on the surface.

The software’s online, changing fast, working well enough at this point to get results.

Bump, as it’s time to start dealing with the coming winter blues, if you know they’re going to bother you.

PS, years ago, I got one of these: http://www.sunnexbiotech.com/
because I’d been using very bright light boxes for winter blues and starting to be concerned about the blue light hazard.

It’s held up well, still helping after a decade or more of use every winter.
Expensive, but worth it for me over the longer term.

Note you can also get the same reduction in blue by putting a $6 Rosco Chroma Green theatrical filter gel over a white emitter.
Replace that every so often, the blue photons are energetic enough to bleach the dyes in the filter after a while.

I moved 1000 miles south to NM and I am “cured”.


I have High Functioning Asperger’s and I can appreciate the problems of having a misunderstood condition.

In my case I have a reasonable control and understanding of my condition by using the very characteristics Asperger’s. :slight_smile: