Full spectrum light
'Full
spectrum' lights (FS) are often reported in the media as being
necessary to treat SAD. We wanted to clarify what FS means.
They are termed full spectrum because the energy is not limited
to the visual waveband (in other words they also deliver a little
ultra-violet, UV), and because the spread of colours is more complete
than with normal fluorescent tubes
When Dr Rosenthal first worked on SAD and light therapy he theorised
that a lack of daylight was the problem so he decided to re-create
daylight as closely as he knew how and therefore used FS lamps.
These early trials were successful and, for a short while, it was
thought that FS lamps were necessary to treat SAD. Since then however,
Dr Rosenthal and others have done a lot of work to see what is
important about the light. The conclusion is that any bright white
light is helpful (recent findings suggest one part of the spectrum
around 470nm green-blue may be the most important) but that UV
light is not necessary and for the sake of caution should be avoided.
Compared to our standard lamps FS lights do produce slightly truer
colours, but they do produce less light and will take longer to
use. Simply changing the lamps in a room to FS type will not increase
the light levels sufficiently to treat SAD.
Pharos lightboxes are virtually full spectrum
because they have an excellent spread of colours (Ra88), much better
than a normal fluorescent tube (Ra60) and traditional full spectrum
lamps with the UV light measure Ra92. So we like to think we have
the best compromise of excellent quality light without any unnecessary
risk.
In his book Winter Blues, Dr
Rosenthal wrote ‘In our early
studies we used lights that [were intended to] imitate the balance
of colours found in sunlight - so called full spectrum light. Researchers
have no evidence that such light is any better than ordinary white
fluorescent light. In fact [these lamps] were designed to emit
more Ultraviolet (UV) rays than regular fluorescents ... Their
potentially harmful effects are a distinct disadvantage… Be
sure that any fixture you purchase includes ... ultraviolet reducing
features.
Is full spectrum light always bad?
Not at all. It's just that when you need to be close to very
bright light, as with a lightbox, other types are preferable. Even
better than full spectrum are Solux bulbs, the truest daylight
bulb ever made.
Morning full spectrum vs. cool white light in Seasonal Affective
Disorder
SLTBR Abstracts. 1989 June
Patients were treated with 2 hours of morning light, either
full spectrum or cool white, in a randomised double blind crossover
fashion for 6 weeks. The two treatments were equally effective
in reducing and/or eliminating SAD symptoms.
Dr. N Rosenthal (who first described SAD
and light treatment) said in May 1992 "There is no justification
for including ultra violet light".
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Comments on this article
Johnjoined 29 Sep 2007 5 posts
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Posted by John, 13:25 29 September 2007True, it appears UV is not necessary for SAD treatment, but it is essential for other processes in our bodies and so should be included in any treatment. There is far to much scare mongering about UV. |
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Posted by Catherine Acosta, 21:06 24 October 2007Are there any light bulbs for SAD which can be used in regular lamps or ceiling lights? Sitting in front of a light box is very confining and difficult to maintain a schedule. Thank you.
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SJGjoined 24 Jan 2008 2 posts
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Posted by SJG, 11:06 24 January 2008Surfing the net trying to buy Solux lamps I came across this page and just wanted to add a comment in reply to Catherine Acosta which may help with her scheduling problem. I primarily bought a SAD lamp - a Phillips Energy Light - because I wanted to have a daylight source for reading in bed. I don't know that either I or my husband have/had SAD syndrome but all I know is that we put that light on every morning either a half hour or an hour before we want to get up and we bask in glorious light, we often doze or fall back to sleep - it's like being on a beach (without the heat). We get up refreshed and energised. In the evening we use it on its lowest setting for reading (not recommended to use the lamp on an effective setting at that time of night or you'll be energised and unable to sleep). There are two lamps in this series and I recommend the one with the timer because then you know how much light you need and it turns itself off afterwards. Now, can anyone tell me where I can get these Solux lights from in the UK?? |
Johnjoined 29 Sep 2007 5 posts
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Posted by John, 13:42 24 January 2008Hi SJG,
I suggest you email Solux direct from their website and ask them (email Phil) - Lumie were the only distributor until last year which is where i bought mine. I think they give out a superb light, but they are basically display case type 12 V halogen bulbs so don't expect to light up your front room with them - they are a great reading/work lamp.
Cheers John |
Johnjoined 29 Sep 2007 5 posts
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Posted by John, 14:05 24 January 2008Catherine,
Try Androv-medical.com, they sell some pretty good full spectrum compact fluorescent bulbs that fit ordinary light sockets. I use one of their 32 W (130 W equivalent) in my bathroom - it's a very blue white 'cold' light but it does help wake you up in the morning. The Solux bulbs being mentioned i believe are better but they need different fittings and are really for display lighting.
Cheers-John |
SJGjoined 24 Jan 2008 2 posts
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Posted by SJG, 13:24 26 January 2008Hi John, yes thanks, after going around the houses on the internet I ordered a clip on light at 4700k direct from Lumie. I couldn't find it on their website because it wasn't on there - I had to ring up. I was a bit put out because I had to pay £69 whereas they are only $50+ in USA and the bulbs work out at 4 x the price. By the way, anyone reading this, I bought this light for white light for colour balancing (I'm a photographer) not for SAD. Have a look at my previous posting (24 Jan) about how I manage getting enough daylight at this time of year. Best wishes Sally |
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Posted by Julia B, 21:25 19 February 2008Hi there
Does anyone know much about Eudemon Purelight and Freshlight Energy Saving Lamps. I've been looking for an affordable SAD lamp and came across www.eudemonuk.co.uk where they sell these incredible sounding light bulbs for under £10.
Julia |
Dr.Sjoined 12 Sep 2008 1 posts
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Posted by Dr.S, 11:21 12 September 2008Hey SJG and John,
your input has been invaluable. I am a doctor and SJG could maybe help me since she's a photographer. Would full spectrum light be good for getting natural skin tones?
If a physician in an examining room has to ientify bluish coloration of the skin or yellowish tinge to the eye would these be visualized better?
Thanks,
Dr.S |
Johnjoined 29 Sep 2007 5 posts
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Posted by John, 15:34 12 September 2008Hi Dr S,
Yes absolutely - the Solux bulbs were developed specifically for accurate colour rendition in display lighting as well as colour matching in paintshops etc i suggest you have a good long look at their website (solux.net) they have masses of data there comparing different light sources and if you have any questions contact Phil at tailored lighting. I would have thought looking at a patient in 'natural' light or the nearest artificial thing to it would be crucial in diagnosing illness.
Cheers
John |
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