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Why do these light therapy devices work for SAD and the like?

Makrosky

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So I have seen these kind of light therapy devices. Apparently doctors prescribe them for the winter. They are not for Vit D since they don't have any UV spectrum. But are supposedly beneficial for SAD and the like.

Why do they work? Is there any benefit on getting a lot of LUXes even with a bad spectrum (assumption) ?

(Example link)


@Hans @StephanF @ecstatichamster @haidut @BearWithMe
 

Peatness

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@Pina I think you are in the UK do you use these there?
I bought one of those lamps many years ago before I discoverd Rays work. I no longer use it and I don't think they are safe at all. The blue light is problematic plus it hurts my eyes. I came across this article a while back

 

Makrosky

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Thanks @Pina

I am wondering though why they work for people. Is it purely the amount of LUX they provide?
 
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Why is it a bad spectrum? Because it has blue light and some UV?

So does sunlight, and being out in sunlight is generally pleasant and good for most people.

I think getting a lot of broad spectrum light, is better than not getting enough light at all. And in my experience mimicking the sunlight spectrum is more favorable than pure red which is very easy to overstimulate you.
 

Makrosky

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Why is it a bad spectrum? Because it has blue light and some UV?

So does sunlight, and being out in sunlight is generally pleasant and good for most people.

I think getting a lot of broad spectrum light, is better than not getting enough light at all. And in my experience mimicking the sunlight spectrum is more favorable than pure red which is very easy to overstimulate you.
Good points. So I guess this things work just by signaling to the retina that it is daylight. There are many light-gated receptors there.

I guess there is not much difference with incandescent lamps besides the spectrum. Or am I missing something?
 

Makrosky

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I bought one of those lamps many years ago before I discoverd Rays work. I no longer use it and I don't think they are safe at all. The blue light is problematic plus it hurts my eyes. I came across this article a while back

It doesn't seem super dangerous judging by the article. It affected only rats with inherited hypertension.
 
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Good points. So I guess this things work just by signaling to the retina that it is daylight. There are many light-gated receptors there.

I guess there is not much difference with incandescent lamps besides the spectrum. Or am I missing something?

It should (in theory) signal most of the same things as daylight, whichever those are - 6500K is the color temperature around noon, and shifts more towards red as the sun sets (2700K etc.)

That said, most LEDs do not even come close to the overall quality of the color spectrum of incandescent, much less the sun, see this:

So this LED light definitely has 'gaps' and lesser amounts of certain wavelengths as compared to natural sunlight - still better than nothing I guess.
 

Hans

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So I have seen these kind of light therapy devices. Apparently doctors prescribe them for the winter. They are not for Vit D since they don't have any UV spectrum. But are supposedly beneficial for SAD and the like.

Why do they work? Is there any benefit on getting a lot of LUXes even with a bad spectrum (assumption) ?

(Example link)


@Hans @StephanF @ecstatichamster @haidut @BearWithMe
Bright light in general helps with SAD. But I'd go for a high watt halogen/incandescent lamp since it also has a lot of red and near-infra red light as opposed to blue light. It's more the ratio between the blue and red that matters.
dT3mv.jpg
 

Makrosky

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Bright light in general helps with SAD. But I'd go for a high watt halogen/incandescent lamp since it also has a lot of red and near-infra red light as opposed to blue light. It's more the ratio between the blue and red that matters.
dT3mv.jpg
Thanks Hans. Yeah halogen/incandescent is what has been recommended always here but I remember seeing someone saying last year that those can be dangerous for the eyes if too bright and for too long? And since the ones I linked are "medically approved" I guess even if they are not beneficial at least they won't harm?

Oh, wait... "Medically approved". Like statins and the vax...

But anyway I'd like to understand if it is a matter of the spectrum or there is more to it. It seems now there is another factor in play which is the CRI and also the kelvins.

So last winter it was the first one I spent in a gloomy latitude and basically what happened is that I was never fully awake nor fully asleep. Quite annoying.

I don't care much about D3 and metabolic effects since those I can cover with supplements but more to signal the retina+brain that it is DAYTIME.
 
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Makrosky

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It should (in theory) signal most of the same things as daylight, whichever those are - 6500K is the color temperature around noon, and shifts more towards red as the sun sets (2700K etc.)

That said, most LEDs do not even come close to the overall quality of the color spectrum of incandescent, much less the sun, see this:

So this LED light definitely has 'gaps' and lesser amounts of certain wavelengths as compared to natural sunlight - still better than nothing I guess.
Excellent. Many thanks.
 

Hans

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Thanks Hans. Yeah halogen/incandescent is what has been recommended always here but I remember seeing someone saying last year that those can be dangerous for the eyes if too bright and for too long? And since the ones I linked are "medically approved" I guess even if they are not beneficial at least they won't harm?

Oh, wait... "Medically approved". Like statins and the vax...

But anyway I'd like to understand if it is a matter of the spectrum or there is more to it. It seems now there is another factor in play which is the CRI and also the kelvins.

So last winter it was the first one I spent in a gloomy latitude and basically what happened is that I was never fully awake nor fully asleep. Quite annoying.

I don't care much about D3 and metabolic effects since those I can cover with supplements but more to signal the retina+brain that it is DAYTIME.
Bright light (unless it's mostly blue light) is never really a bad thing. Just put it at such an angle that it doesn't shine in your eyes. Peat mentioned that bright light for only like 10-30 min daily was enough to prevent SAD. Bright light in the morning is key also.
 

Makrosky

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Bright light (unless it's mostly blue light) is never really a bad thing. Just put it at such an angle that it doesn't shine in your eyes. Peat mentioned that bright light for only like 10-30 min daily was enough to prevent SAD. Bright light in the morning is key also.
Thanks. Then I guess their use is for the eyes (directly or indirectly shined). Not through the skin as redlight/vit d3 devices.
 

Makrosky

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Bright light in general helps with SAD. But I'd go for a high watt halogen/incandescent lamp since it also has a lot of red and near-infra red light as opposed to blue light. It's more the ratio between the blue and red that matters.
dT3mv.jpg
btw Hans there are LEDs these days that have a much better spectrum than the one in the graph. Doesn't have to be that bad.
 

Peatness

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It doesn't seem super dangerous judging by the article. It affected only rats with inherited hypertension.
I'm not a rat last time I looked but I come from 3 generations of hypertensive women.
 

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