Now that winter is fast approaching, my husband is beggining to have trouble with seasonal affective disorder. I’ve been told that a sunlight replacement lamp would probably help, however the ones online are pretty expensive. Then a friend told me that the full spectrum light bulbs you can buy at places like Wal Mart are the same thing. Is this true? If so, do they need to have a certain type of fixture (for instance, do they lose their effectiveness if the light has to pass through glass, etc.)?
All the research that I’ve seen indicate that it is not the spectrum that’s important, it’s the intensity of light (measured in lux). So while a full-spectrum bulb might be nice, unless the lamp can provide enough energy to make it shine up to 10,000 lux, it’s not proven to help SAD.
What I don’t know is if a normal lamp can do that depending on the lightbulb.
Lux is Lumens per square meter, and most bulbs come with a lumen rating.
Here are some typical numbers:
Cool white 40W fluorescent 2,960 lumens
Incandescent 150W 2,600 lumens
High Pressure Sodium 150W 15,000 lumens
Halogen 500W 8,000-12,000 lumens.
My wife uses a 500 watt halogen work light, like the $10 cheapie here; sits within a few feet of it. Insofar as light therapy can be proven to work, this does the job.
So a halogen lamp would be sufficient? Do you have to have a certain proximity to the lamp for it to work?
Within a few feet. If LaurAnge’s figure of 10,000 lux is correct, which I suspect it is, because it’s a reasonable fraction of the intensity of full sunlight, and your lamp puts out 10,000 lumens, you need to be close enough to the light that all of it’s output covers an area of 1 square meter, or less.