The Department of Energy has a prize, called the L Prize, for a new light bulb that gives off same light as a 60-watt incandescent bulb but uses much less energy. Philips has submitted what it believes will be the winning entry. For the last decade, I’ve tried to avoid fluorescent lights at night. Ordinary fluorescent lamps emit light with far more blue than incandescent lamps and mess up my circadian-timing system. That systems appears insensitive to incandescent light. Squirrels are like me, a study suggests.
Fluorescent lights are close enough to sunlight to affect our circadian system; incandescent lights, being much cooler than the sun, are invisible to it. The timing of exposure matters if it varies from day to day; exposure to fluorescent lights at varying times is like travelling back and forth across time zones. Everybody grasps that travelling across time zones makes it hard to sleep at the right time; what is less understood is that time-zone-crossing travel affects the depth of sleep because it reduces the amplitude of the circadian oscillation. If you are exposed to fluorescent lights at night now and then, you will sleep less deeply. So I try hard to avoid fluorescent lights at night. I avoid supermarkets and subways, for example.
I discovered all this when I discovered the effects of morning faces on my mood. After I travelled back and forth across time zones, the effect took three weeks to fully return. Nothing else had changed. I conclude that it took three weeks in the same place for my circadian oscillator to return to maximum amplitude. And one evening in which I was exposed to an hour of fluorescent light was enough to get rid of the faces effect for a few weeks. The ubiquity of fluorescent lighting has made it hard to study this effect in other people.
Maybe fluorescent lighting is behind some of the dreadful effects on sleep of shift work.
A couple of links claiming connections between cancers and night-time artificial lighting, presumably by disruption of circadian rhythms:
https://www.sciencedaily.com/releases/2009/02/090203135015.htm
https://www.rd.com/living-healthy/artificial-light-a-hidden-cancer-risk/article128447.html
(The Science Daily page says that energy-efficient light bulbs are much brighter than incandescent lights. I’m not sure what they mean by that. Obviously they’re brighter watt-for-watt, but that’s the whole point.)
My personal bugbear is bright ceiling lighting. Having something shining intensely down on me from overhead when it’s dark outside really unsettles me. That said, I don’t think it much affects the amount or quality of sleep I get, but I haven’t gathered any halfway decent data to support that claim.
This is really interesting.
I instinctively dislike fluorescent lighting. Now that you mention it, I especially dislike them at night (perhaps because they’re more obvious then). Libraries, for example, with their flickering, buzzing lighting, I find horrible. I find I like the ‘warmth’ of incandescents. This is why the idea of making incandescents illegal makes me angry. I will start up a trade in illegal incandescent lightbulbs before I start using fluorescents (alternately, I would move to candle-light before using fluorescents).
Hmmm… My flat-screen monitor is internally lit by a flourescent bulb. I wonder if that is having an effect on my sleep. After all, I’m staring directly at it for an hour or two before bed.
My personal researches shows that pc monitors or tv are NOT effects on your sleep. So John is right.
Also “..claiming connections between cancers and night-time artificial lighting, presumably by disruption of circadian rhythms..” – it’s just a.. mmmm.. errm… it’s not true.
Have you considered trying daylight-spectrum CFLs? Also, talk about burying the lead in that article – the only place early on where it’s mentioned the Philips bulb is LED based is in the caption.