Become a fan of Slashdot on Facebook


Forgot your password?

Exposure to Backlit Displays Reduces Melatonin Production 192

alphadogg writes "Researchers have discovered that relatively little exposure to tablets and other electronics with backlit displays can keep people up at night by messing with their circadian rhythms. The study from the Lighting Research Center at Rensselaer Polytechnic Institute showed that a 2-hour exposure to electronic devices with such displays causes suppression of the melatonin hormone and could make it especially tough for teens to fall asleep. The study, funded by Sharp Laboratories of America, simulated usage of such devices among 13 people using special glasses/goggles and light meters"
This discussion has been archived. No new comments can be posted.

Exposure to Backlit Displays Reduces Melatonin Production

Comments Filter:
  • by Anonymous Coward on Monday August 27, 2012 @10:05PM (#41144773)

    Surely 13 people is too few to draw meaningful conclusions?

  • I can attest... (Score:5, Interesting)

    by suprcvic ( 684521 ) on Monday August 27, 2012 @10:08PM (#41144795)
    I've found that over the last year or so I've had trouble falling asleep and getting deep restful sleep. I started getting off the computer about an hour before I plan to go to bed, taking 3mg of Melatonin and reading a book. Now I'm getting the best sleep I've ever had. On that note, good night.
  • by Wrath0fb0b ( 302444 ) on Monday August 27, 2012 @10:11PM (#41144819)

    I think all /.ers have known this since about age 15. I used to go into a phase where I'd be up every night later and later until I was going to sleep at 6AM and waking up at 2PM. Eventually I'd lose a day and "reset" to a normal time only to inch back later ...

    Anyway, here's a plug for the awesomesuace that is f.lux [], which removes the blue hues from your monitor (since blue light is more associated with circadian rhythm than red) when it's supposed to be night. I am not associated with the makers of f.lux in any way except being a hopeless devotee and mentioning them to anyone within earshot that mentions difficult keeping a normal sleep cycle.

  • by queazocotal ( 915608 ) on Monday August 27, 2012 @10:18PM (#41144859)

    I find that works.
    Almost all my devices will not dim adequately.
    Typical dim range is down to 1:128 or so.
    1:1000 is much better for use in true dark.
    I have to in addition use extra software to increase the dimming, or set dark fonts and backgrounds to get it truly comfortable in a dark room.
    This would be a free mod to do in hardware.

  • Re:Explains a lot (Score:4, Interesting)

    by Mista2 ( 1093071 ) on Tuesday August 28, 2012 @12:06AM (#41145393)

    f course, I've been reading with my iPad and iPhone in bed.
    1 I find that the biggest problem of falling asleep with the iPad is that it hurts much more than my iPhone when you fall asleep and it hits you in the nose.
    iBooks and Kindle also have a night mode 8) this stops the wife complaining of the LCD glow.
    And I've started reading 2312. If this doesnt put you to sleep, nothing will.

  • Re:N = 13? (Score:5, Interesting)

    by dutchwhizzman ( 817898 ) on Tuesday August 28, 2012 @03:13AM (#41146027)

    Apart from my joke response, yes, N = 13 is way too small here. Not only that, but the circumstances are questionable as in to how the light was administered. No tests have been done with other light sources generating other spectrums either.

    Someone I know has done some rather ground breaking studies in the past, resulting in Philips selling light therapy lamps to cure winter depression. This was the first, or at least the first serious commercial supplier of such lamps, working with clinically proven effectiveness. I know what type of things he had to study to come up with what exactly works and what doesn't, so he would have scientific proof as well as proper clinical tests to prove that the light therapy fixtures he came up with actually worked and what was the "effective ingredient". He also had to make them in such a way that using them would not be too much of a burden to people, getting a usable balance between comfort while the light was on and duration. The higher the light intensity, the shorter exposure required.

    One of the things he found, was that below a threshold, your body simply wouldn't react when it came to winter depression treatment. For sleeping (another study he's continuously working on), however, any light source he tried, was an influence, even at very low intensities. He found that things like dream intensity, REM patterns and all that increased when people were in a totally dark room. Even with your eyelids shut, your body still reacts to the light.His most recent study found that by exposing senior citizens to a high dosage of "day light" slows and even can improve conditions like dementia and is very effective against depression.

    For all these, to get absolute proof, he had to do double blind field tests on large control groups, in their natural environments, because the plain effect of just exposing them to a test was itself an influence already. Also, as mentioned before, the spectrum and getting over a certain threshold was significant in the senior citizen experiment. He had to do tests in several elderly homes for long periods of time, using different light sources and amounts of light per center, for 6 months time and gather all the data on depression, dementia, number of complaints, amount of people taking an afternoon nap and all that, plus the comparison to the situation a year before, to get any significant data to work with. All in all, his study in senior citizens used more than a thousand subjects. Even with that number, it was hard to get to a level of clinical proof that using intense artificial daylight exposure inside elderly homes was beneficial to the health of the inhabitants.

    For the sleeping pattern tests, he is exposing people to different intensities and spectrums for months, using dozens of test subjects each year, for years in a row. People tend to have different sleeping patterns depending on how their day went, the temperature, their general health and the season already. It was common sense to assume that and he quickly found out that the deviation was such that he had to work with large groups and take a lot of samples to deal with that. In order to get any significant results, he'll have to figure out what the standard deviation is per subject, for the entire group and use that to come up with base levels in which he can find differences that can only be attributed to his light testing.Now, how do thirteen lab monkeys with apparatuses stuck to their eyeballs just before they were sent to bed compare to that again?

"If it's not loud, it doesn't work!" -- Blank Reg, from "Max Headroom"