Either one accomplishes much the same effect by adjusting the (apparent) color temperature of your screen depending on time of day. It distorts colors, if you fancy yourself a photographer, but your eyes will thank you.
In psychology grad school, I learned that a single blue photon hitting the back of the is sufficient to cause a measurable shift in melatonin output. Note: measurable is not the same as deleterious, but flux doesn't even eliminate all the blue light your computer is putting out, let alone the other sources in your house.
The only solution, baring blacking out all your windows, or removing all modern light sources from your house, or replacing them all with red lights, is 0.3-0.5 mg of melatonin a few hours before bed. Note: it's sold in the stores in 5 mg tablets - an order of magnitude too much.
I've been using 1mg lately (the lowest I can find) and they work much better. Still help make me drowsy, but without waking up in the middle of the night.
I recommend experimenting with amounts (I break my pills up) and finding the amount that works for you.
You also have to take it an hour or so >before< bed.
I do know people that have had it work very well for them, however.
Most of the range of "alerting" light for humans is between 11-14 log photons/sec/cm^2, so one photon is sort of an enormously huge understatement.
For sleeping, it is good to be in a dark room, but for winding down, you won't mess yourself up with dim light.
Also, I think it may be poor advice for most people to take melatonin except for "shifting the clock" e.g., jetlag. Seeing extra light in the morning is enough to entrain the clock for most people.
I have absolutely no scientific evidence in favor of its effect on sleep... but on a whim I picked up a yellow CFL bulb (originally advertised as not attracting bugs to your porch) and it makes a pretty nice lamp for reading in bed. If I go to another room of the house and turn on the light, I'm often surprised by how blue everything seems by comparison.
What is the 'noise' of your retina? How often do the nerves attached to your cones (the blue sensitive ones) just fire spontaneously? It's not 0 even when you are asleep. Just from some basic reasoning you can work out there is a noise floor that your body (each likely unique) learns to ignore. From what /u/herf here says, it's a log scale of input (similar to most detector systems).
From UpToDate: " Nocturnal melatonin concentrations can also be affected by drugs that interfere with the transmission of neurotransmitter signals to pineal cells (like propranolol, a beta-blocking agent) or those that inhibit melatonin's metabolism (like 8-methoxypsoralen), and by a few drugs that lack clear links to melatonin's synthesis or metabolism (eg, caffeine, ethanol).
Nocturnal melatonin secretion is also suppressed by a relatively dim 100 to 200 lux when pupils are dilated. The most potent wavelength for suppressing melatonin secretion appears to be 446 to 477 nm, which differs from the peak absorbances of the photopigments for vision.
Prolonged use of portable light-emitting devices (laptops, tablets, smartphones) before bedtime can have a negative impact on melatonin secretion, circadian rhythms, and sleep. One study compared the effects of reading an electronic book illuminated by a light-emitting device (LE-ebook) versus a printed book (by reflected light) for four hours prior to bedtime for five consecutive nights. Subjects in the LE-ebook group had suppressed melatonin concentrations in the early part of the night, a delayed endogenous circadian melatonin phase, felt less sleepy before bed, took longer to fall asleep, and reported feeling sleepier the following morning. These observations suggest that evening use of light-emitting devices may contribute to phase-delays in the circadian clock and difficulty initiating sleep."
Prehaps /u/herf could tell us about the study that looked at ebooks and if they used f.lux or not as a control.
UpToDate's cited sources are:
Mayeda A, Mannon S, Hofstetter J, et al. Effects of indirect light and propranolol on melatonin levels in normal human subjects. Psychiatry Res 1998; 81:9.
Garde E, Micic S, Knudsen K, et al. 8-methoxypsoralen increases daytime plasma melatonin levels in humans through inhibition of metabolism. Photochem Photobiol 1994; 60:475.
Wright KP Jr, Badia P, Myers BL, et al. Caffeine and light effects on nighttime melatonin and temperature levels in sleep-deprived humans. Brain Res 1997; 747:78.
Röjdmark S, Wikner J, Adner N, et al. Inhibition of melatonin secretion by ethanol in man. Metabolism 1993; 42:1047.
Ekman AC, Leppäluoto J, Huttunen P, et al. Ethanol inhibits melatonin secretion in healthy volunteers in a dose-dependent randomized double blind cross-over study. J Clin Endocrinol Metab 1993; 77:780.
Brainard GC, Rollag MD, Hanifin JP. Photic regulation of melatonin in humans: ocular and neural signal transduction. J Biol Rhythms 1997; 12:537.
Aoki H, Yamada N, Ozeki Y, et al. Minimum light intensity required to suppress nocturnal melatonin concentration in human saliva. Neurosci Lett 1998; 252:91.
Brainard GC, Hanifin JP, Greeson JM, et al. Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor. J Neurosci 2001; 21:6405.
Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci U S A 2015; 112:1232.
If you want to see fluence-response curves for single-wavelength lights, this is a really neat reference: http://www.cet.org/wp-content/uploads/2014/06/Gooley-2010-Sc... - this one makes the case for some cone interactions when people are sensitized to darkness.
And the mostly-consensus view on melanopsin response is presented here: http://lucasgroup.lab.ls.manchester.ac.uk/research/measuring...
Edit: the name notwithstanding, it does more than adjust brightness, including filtering color temperature, much like f.lux
Why install N pieces of software when 1 piece of hardware will do?
Maybe not your lightbulb!
Kudos!
I was actually bothered by the uneven distortion so I created multiple display profiles with a monitor calibrator at different color temperatures and then wrote a simple tool to load them at the appropriate time: https://github.com/stefantalpalaru/iccloader