Apple's Night Shift May Have Zero Effect On Sleep (macworld.com)

eggboard writes: While blue light emitted by monitors and mobile displays has been widely cited as a cause in disrupting people's circadian rhythm, the evidence is thin: a narrow range of blue spectra might not be the problem (it may be a more complicated interaction), brightness may be more important, and Night Shift's (and f.lux's) effects are probably too negligible anyway. Apple's Night Shift feature lets you adjust the color temperature of your display to the warmer end of the spectrum. Apple notes, "Many studies have shown that exposure to bright blue light in the evening can affect your circadian rhythms and make it harder to fall asleep."

Comments

Duly noted.

[Just Some Guy]

Even if it doesn't, I very much love the aesthetics of the warm display at night. I think it's less jarring going from looking around a warmly-lit room to a reddened display, and whenever I turn f.lux or Night Shift off it's like I'm suddenly staring into the sun.

If it helps my sleep, cool. If it doesn't, I still like it.

Re:Duly noted.

[fiver-hoo]

Yep. Same here. If it happens to improve my sleep, it's merely a bonus. I've never cared. It is simply much more pleasant to use a display with a warmer color temperature in the evening.

Re:Not a sham, just not quite there.

[PopeRatzo]

Yep. f.lux is definitely a winner. And when I'm paying attention when the display changes from day to night, it reminds me that the sun has just set and allows me to pause for a second to note the passage. It reminds me that there are other things to do in life and not to lose track of time.

seems to help me

[epine]

I'm pretty sure redshift (which I'm running under PC-BSD) assists in managing my sleep disorder. I have three 24" displays. It's a lot of light. The last time redshift was inadvertently disabled, at some point in my evening work session I looked at the clock and went "holy shit, it's past midnight!" This does not comply with my sleep program.

My disorder is N24. After many years of personal study, I have fairly high confidence that while it is supposed to help, blue light in the morning influences me very little, if at all (I have a professional treatment box). Blue light at bedtime does, however, seem to make things worse.

What did cure my disorder was 0.75 milligrams of sustained-release melatonin roughly six hours before bedtime.

Before I tried SR melatonin, over several years of experimenting with non-SR melatonin I only ever managed to reduce my 25.5 hour circadian day to 24.25 hours. Drifting 15 minutes a day doesn't sound like much, but it's substantially less desirable than the full cure.

Apparently many people don't get groggy after taking melatonin mid-day. It happens to hit me pretty hard.

Recently I read a paper about how melatonin increases circulation to the hands and feet without increasing core metabolism, with the net effect that core body temperature declines (apparently, enhanced vascularization of the nail beds makes them efficient radiators). Since I started wearing warmer clothing after my daily melatonin dose, my early evening grogginess has declined by about 2/3rds. It doesn't hurt either to throw in some "orthostatic challenge". This was how the stuffy research paper described "standing up and walking around".

Given how blue light works, there's not much point shielding yourself from one source if you end up getting exposed to another source. The reading lamp in my bedroom is a yellow bug lamp. Added bonus: it's extremely slow to warm up, so it's a great lamp to turn on for a few seconds in the middle of the night, if my back pain treatment arsenal rolls out of reach under the bed.