I have heard that fluorescent lights are generally bad for you. The explanations range from the light being in the blue area of the spectrum:

The signature "glow" of fluorescent lighting is created by sending an electrical charge through a special gas enclosed within the fluorescent light tube. This glow, which is "cold" compared to the rather "hot" burn of an incandescent bulb, gives off light that often falls into the blue-green end of the spectrum. It is a color that is very different from the spectrum color of natural sunlight or incandescent lamps. The problem with this blue spectrum light is that it is so completely unnatural and may likely affect mood in human beings. Exposure to fluorescent lighting over long periods of time has been known to cause depression.

... to the "flicker effect":

Because of their construction, fluorescent light fixtures flicker on and off very rapidly during normal operation. While this flickering is not obvious to most workers it is a modulation that is noted by the brain on a subconscious level. This flickering effect is believed to cause "fluorescent light headaches," tension and even hostility in workers in the same way flickering lights often cause bad reactions in people suffering from epilepsy.


Everyone's favorite purveyor of "alternative medicine" (i.e. "quack"), Dr. Mercola claims:

Even back in 1980, scientists reported that cool-white fluorescent lighting produced increased levels of the stress-producing hormones ACTH and cortisol. They noted that their findings explained the agitated mental and physical behavior of children sitting all day under artificial lights, and recommended a change to illumination similar to that of natural light.

The eHow.com article references a study that indicates that exposure to sunlight is beneficial:

The Wilkins-Nimmo study showed that employees exposed to natural sunlight suffered far less depression than employees exposed to fluorescent lights during the work day.

However, I don't believe that can be extrapolated to "fluorescents cause depression".

Does exposure to fluorescent lighting have a real risk to mental or physical health?

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    The two key objections (flicker and colour) are not inherent to fluorescent lighting. The colour is tunable by choice of phosphor mix and can replicate tungsten light (which is unnaturally warm compared to sunlight anyway) or sunlight (which many find "cold"). And lights can be driven with high frequency sources rather than the 50 or 60Hz of mains electricity which is the source of flicker. – matt_black Jan 10 '12 at 14:26
  • not only that, but as you noticed yourself the second assertion ("exposure to sunlight is beneficial") says nothing about fluorescent light. If the absence of sunlight caused stress, any artificial light could do the trick (or indeed no light at all). – jwenting Jan 13 '12 at 6:24
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    @matt_black The mains is rectified in old fluorescent lighting, so you actually get 100/120 Hz - very few people will be able to see that (apparently colour change through the cycle for which, I believe, coloured glasses are recommended). Modern fluorescent lighting operates with cycle periods much shorter than the average length of time it takes the mercury to emit light - so effectively continuous. People are most sensitive to flicker in the 6-10 Hz range. Flicker seen in defective lighting is apparently unrelated to the frequency the tube is being driven at. – Tom Hawtin - tackline Feb 13 '13 at 3:14
  • There have been studies to measure eye fatigue from reading under different lights. Reading has alledgedly been found to more tiring the more the light flickers. I wouldnt be surprised if alot of cheap CFL are not designed to be reading with. Phosphorus should have a fade time of about 5ms, same as turning off the light, so it's surpsing it should vary so much in brightness. – com.prehensible Dec 15 '14 at 19:28

Not an exhaustive answer, but some pointers:

  • The HESE (Human Ecological Social Economical) Project's Artificial Light in the Environment: Human Health Effects page states "more study is needed". (In other words, "give us more of your money"). It does however cite an exploratory animal study (S.L. Gabby (1961), Observations on the effects of artificial light on the health and development of mice) that showed reduced lifespan and increased cancer rates among lab mice exposed solely to fluorescent rather than incandescent light. In my opinion, the study mentioned is flawed because of the very small sample size (just 30 pairs of mice in either group).

  • CRS Light sells "full spectrum fluorescents" that are supposedly "much easier on the eyes". This is hardly authorative, of course. (I wonder what ICANN would say about their .org domain being used for a commercial venture, but I digress).

  • MedHelp has an eye doctor respond to a question claiming that "If one out of four people were sensitive to florescent lighting it would have been abandoned decades ago. ". Not sourced of course, but common sense (ADA, OSHA, etc. would come down like a ton of bricks on fluorescents if there were a far smaller number of people than claimed who have medical problems because of them).

  • http://www.livestrong.com/article/122360-health-effects-fluorescent-lighting/ mentions a study (apparently by Mayo clinic) claiming fluorescents can help cure certain skin conditions, and a newspaper article claiming increased stress levels because of them (of course the Daily Mail is hardly a scientific publication).

  • http://www.fehrmanbooks.com/health-effects-of-fluorescent-lighting mentions a number of studies claiming all kind of medical problems because of fluorescents, ranging from agoraphobia to cancer from just being exposed to the light. I've my doubts about this, as it seems to be a site set up to push people into buying some product.

To summarise: seems there are some studies showing negative effects, some showing positive effects, some showing nothing at all. Guess is all (as so often) depends on how you set up the experiment and interpret the results afterwards.

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    There are no restrictions on commercial use in .org and haven't been for a while. I'm sure all ICANN would say (or, rather, PIR) is "thank you for the money, can we interest you in another domain?" – derobert Jan 13 '12 at 17:58
  • Some of these resources are great, but as you say, this isn't an exhaustive answer. Surely there has been at least one major study comparing fluorescents to "black body" lighting (incandescent and halogen)? – aaaidan Mar 9 '12 at 23:12
  • @aaaidan not that I could find (but I'm no expert in the field, apart from having done some research over a decade ago in optimal lighting for acquariums, which mostly focussed on the ideal wavelength distribution for various fish species, solely for personal interest, never done a writeup and publication of that literature study). – jwenting Mar 14 '12 at 6:11

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