I'd love to see the something from Lumie [0] analysed/reviewed like this in the UK. For instance the Lumie Vitamin L [1] is an LED version I'm interested in getting. I suffer for terrible migraine with aura [2] verging on chronic [3] that's started to beat my maximum dose of beta blockers, so I'll try anything!
I suffered frequently from terrible migraine until a chiropracter worked my spine. After that it was gone, except for one time months later. That was in my teenage years following a growth spurt and neuroactive narcotics abuse. The closest I got to feeling like that again was from too little sleep and work out, coupled with too much coffee and cigarettes. I'm still luzzled how likely blocked arteries figure into this. Still I get a numb hand from time to time.
The conclusion about the UV diffuser isn't quite right. It clearly preferentially attenuates around 365nm for example. Good article and solid conclusion though.
Really the absorption measurement should have been taken using a broadband lamp (an old light bulb would do). Using a CFL, the signal to noise in the attenuation region is pretty poor to begin with.
Yes, and it's not clear it attenuates total transmitted power significantly on other wavelengths. Just putting in a diffuser you expect more light scattering out of the rays going towards (what I presume is a) optical fibre, but most of that power just goes somewhere else, it is not absorbed.
Can anyone tell how to measure the R1-R14 [0] values of a LED lamp? It seems like a sort of a Gretag-Macbeth [1] card is used. Can I use a photospectrometer [2]? I'd like to measure R9 [3] & R13 myself.
There seems to be little overlap in the Munsell colors between the two[1][2]. There does appear to be a variant that uses some ColorChecker patches[3], or there's another calculation that just goes directly off of the light's emission spectrum[4], assuming your spectrometer has enough resolution. I think in practice, an ad-hoc comparison of the ColorChecker under daylight/D65 and the light in question will yield good enough results.
Oddly, the article neglects to mention the whole rationale for boosting the blue light in these kinds of therapy lamps: blue light (wavelengths in the low to mid 400 nm range) has the greatest effect on circadian rhythm.
It makes me wonder if there are geographic/climactic components to seasonal affective disorder.
In Vancouver, it's going to be in the "bone-chilling" upper 40s today, while a few degrees south near me it will be in the low 20s. A few degrees south means that even though we have colder weather, we'll have more hours of brighter sunlight. In England, further north than either of our locations, it will be in the low 50s (those temperature ranges are 8, -6, and 11 degrees Celsius, respectively).
Would more people suffer from SAD in more northern locations because there's simply less sun, but they'll choose to live there because it's warm enough as a result of proximity to ocean currents? Or would fewer people suffer from SAD because they can spend more time outside where it's warmer?
[0] https://www.lumie.com/
[1] https://www.amazon.co.uk/Lumie-Vitamin-Lightbox-Effective-Th...
[2] https://www.migrainetrust.org/about-migraine/types-of-migrai...
[3] https://www.migrainetrust.org/about-migraine/types-of-migrai...