All day SAD lamps - dangerous or not?

January 16, 2021 5:59 AM

Is it a bad idea to get a SAD lamp for my desk? Should exposure to them be limited?

Working indoors I get fed up with the gloomy artificial light. I have a SAD lamp which I like and wondered if it might be good to have one as a desk lamp but see cautions only to use those for 60/90 mins. This seems weird to me, unless there's something up with the UV they produce, as these lamps only kick out a few thousand lux and on a bright sunny day outside you'd be exposed to much more than that all day without ill effect - what are the time limits about, and would it actually be safe to get bright desk lamp like a SAD lamp - what, if anything, am I missing? Or is there something else that I should get instead to provide bright daylight like light?

posted by Flitcraft to Health & Fitness (14 answers total)

According to the Mayo Clinic, there are some side effects from using a SAD lamp too much - nothing permanent, and some just may be uncomfortable (nausea, eye strain). But some manic behavior is a potential side effect as well - and is apparently common enough that it was turned into a plot point in an episode of the show Northern Exposure.

I'm not sure there's enough research to explain why these effects might happen, but the mania is definitely something to think about.
posted by EmpressCallipygos at 6:44 AM on January 16, 2021 [2 favorites]

I can only speak to personal experience, but when I start using my SAD lamp again after not using it for a while, I have to slowly increase my time using it. If I use it for too long too soon, I get headaches, nausea, and can sometimes feel panicky/irritated. I've never used it for more than 45 minutes at a time, though!
posted by miserable-mild at 6:59 AM on January 16, 2021

I'm all for SAD lamps, but the posters above are right about the side effects of overexposure. As an alternative, would you consider some kind of temperature-adjustable lighting? I just got a smart bulb for my main workspace lamp, and now I can make it feel quite sunny during the day and dial back the intensity in the evening. The one I got was the Philips Bluetooth-enabled "white ambiance" bulb, which was extremely easy to set up and definitely cost less than a SAD lamp. I think Ikea and other vendors have similar options.
posted by ourobouros at 7:27 AM on January 16, 2021 [1 favorite]

Response by poster: Why doesn't daylight have these effects though? Bright daylight is ca. 111,000 lux and people work all day outside without developing mania
posted by Flitcraft at 7:40 AM on January 16, 2021

I use my SAD lamp all day in my office. I try to remember to switch it to medium after 12, but I love it. I live in the PNW, and everything is gloomy.
posted by Valancy Rachel at 7:52 AM on January 16, 2021 [1 favorite]

Why doesn't daylight have these effects though? Bright daylight is ca. 111,000 lux and people work all day outside without developing mania

Sunny weather is indeed a mania trigger for some people. There are apparently studies showing that hospitalizations for mania peak in the summer and fall, and anecdotally a lot of people who already have a bipolar diagnosis say that summer is especially bad for them.
posted by nebulawindphone at 8:43 AM on January 16, 2021 [7 favorites]

Also, summer weather ramps up very slowly. I wouldn't be surprised if the risks are higher for people who go from zero to sixty with a lamp.

(None of this means you shouldn't use it all day. Just... keep an eye out. Mania is rare, but it's very dangerous, and catching it early is very, very important. Watching yourself for signs seems prudent.)
posted by nebulawindphone at 8:50 AM on January 16, 2021

Best answer: I live in Scotland where it’s dark about 3.30pm in midwinter and light levels are often low through the day, and use a 10,000 lumen lamp. I usually have it next to my computer all morning with no ill-effect, switch it off around lunchtime because i just don’t feel the need at that point. I sometimes put it back on for an hour or so as it gets dark and don’t have any issues.
posted by penguin pie at 9:24 AM on January 16, 2021 [1 favorite]

SAD lamps have almost an identical effect to drinking coffee on me. For me, that's not good, so I don't use them. As with coffee, how much SAD lamp you can tolerate in a day will vary depending on you.
posted by aniola at 9:51 AM on January 16, 2021

If I use my SAD lamp all day, especially if I keep it on in the evening, I will have trouble sleeping that night. Ymmv but I think it throws off my body clock if I use it for too long.
posted by k8lin at 10:06 AM on January 16, 2021 [2 favorites]

Best answer: Most SAD lamps are going to have a white/blue light that's most appropriate for morning use. Blue light is thought to be a melatonin suppressant, and bright light is a "zeitgeber" (tells your body what time of day it is, and blue light in the natural world is usually seen in the morning), so using it into the afternoon and evening could have the effect of throwing your body rhythms off a bit.

If it were me I would probably use it before lunch. And if I really wanted it in the afternoon I might point it away from me.
posted by hungrytiger at 10:31 PM on January 16, 2021 [2 favorites]

Many SAD lamps have a lower setting that can be used for extended periods. I think, too, if you move it a foot or so farther away or angle it away from your face you might be able to safely use it for longer periods.
posted by QuakerMel at 6:39 AM on January 17, 2021

The lux comparison is not going to be meaningful for UV exposure, because it's a measurement of all light across the spectrum. I don't know what the actual spectral output of your lamp is compared to sunlight. but the comparison itself is potentially like asking why you shouldn't eat a tablespoon of straight salt, because you eat a whole cup of salty crackers with no ill effect. Remember also that if you are spending all day outside in bright sun you ought to be wearing sunscreen and sunglasses to protect your eyes.
posted by Lady Li at 7:54 AM on January 17, 2021

Response by poster: Thanks, this is all very helpful. I see the medical grade ones filter out UV and that there are lamps now with settings to allow you to shift to softer or to warmer light as the day goes on to avoid upsetting sleep patterns at night.
posted by Flitcraft at 5:34 PM on January 17, 2021