This article refers to "moderate" (100 lx) light exposure - this amounts to an overhead light on in the room for the entire duration of sleep.<p>I would say an overhead light is a significant amount of light, but wonder how low the threshold is for sleep disruptions. Living in an urban environment, there's a non-negligible amount of ambient light that makes its way in. I don't use a set of blackout curtains, but I know several friends that say it makes a real difference.
The research discusses 100 lux for one whole night, which is quite a lot (indoor levels range from 100 to 1000 lux, outdoors from 10k on a cloudy day to 120k with direct sunlight at noon.) Like others here, I’m curious about other strengths of light - I assume up to 0.1 lux is fine, as moonlight is typically 0.05-0.1 lux, but what about between 0.1 and 100 lux? And what about light exposure during part of the sleep cycle? There’s quite a lot of sleep research, much of it poor quality, so I’d be grateful for any specific study suggestions.
One night? You could probably repeat this experiment with fart stench or any other obnoxious irregularity and find impairment of glucose tolerance at a decent p value.<p>I see the headlines now: "Fart stink during sleep impairs cardiometabolic function." So yeah, guess the wife is getting diabetes if I don't move to the dog house.
I find these stickers helpful for a ton of little lights in the bedroom<p>LIGHT DIMS Black Out Edition - <a href="https://www.amazon.com/dp/B009WSN8PK/ref=cm_sw_r_cp_api_glt_i_XQ0TFF4B87XMM1TFAGXF" rel="nofollow">https://www.amazon.com/dp/B009WSN8PK/ref=cm_sw_r_cp_api_glt_...</a>
It reminds me of this article [0], a very interesting read on "surviving" winter in Sweden (and Northern latitudes in general). It ends with how in summer things are flipped and everyone complains about how poorly they sleep.<p>[0] <a href="https://www.ft.com/content/180f3428-1923-11e9-b93e-f4351a53f1c3" rel="nofollow">https://www.ft.com/content/180f3428-1923-11e9-b93e-f4351a53f...</a>
I live in the north part of the north hemisphere. It's bright outside the entire 24 hours for almost a month during summer. I use a sleep mask to combat it and the last 5 years I feel like I regained sleep during the summertime. Last year I purchased a Manta Sleep mask and they are next-level good. Total darkness and really easy on the face. I have no affiliation with the brand, just a really happy customer of theirs.
Could this effect be explained otherwise by "disruption of normal sleeping environment"? Presumably all of these people are used to sleeping with dim lights. What would the effect be on subjects who were used to 100 lux light?<p>My intuitive sense is that light at night has some harmful effect. On the other hand, I live at a latitude where summer nights are very bright, and I and my fellow residents generally get used to it. Perhaps the effect diminishes?<p>Are there people with sleeping habits such that they would find darkness similarly disruptive?
Research on Blue light and sleep:
<a href="https://justgetflux.com/research.html" rel="nofollow">https://justgetflux.com/research.html</a><p><a href="https://en.wikipedia.org/wiki/Melanopsin" rel="nofollow">https://en.wikipedia.org/wiki/Melanopsin</a> :<p>> <i>Melanopsin photoreceptors are sensitive to a range of wavelengths and reach peak light absorption at blue light wavelengths around 480 nanometers.[30] Other wavelengths of light activate the melanopsin signaling system with decreasing efficiency as they move away from the optimum 480 nm. For example, shorter wavelengths around 445 nm (closer to violet in the visible spectrum) are half as effective for melanopsin photoreceptor stimulation as light at 480 nm.[30]</i><p>Under Melanopsin > infobox > "Biological process", e.g. "entrainment of circadian clock by photoperiod" and "regulation of circadian rhythm" are listed.
I love studies like this. I know, I know. "It's just a study." But it means that people are having new thoughts about how the body responds to its environment and enters into chronic disease states.<p>Some of our "new ideas" about diseases are actually maybe not all that crazy [1].<p>Every time I see one of these potential connections, my brain jumps to generate new hypotheses for everything around it. I sometimes wish I was a PI looking into these things.<p>For instance, this article made me think that perhaps children being exposed to night lights upsets their metabolic behavior in early development enough to lead to long term neurotransmitter dysfunction and desensitization. ADHD. Just a hypothesis. Totally unsupported. Probably not a contributor. But I'd love to have access to journals and data and test these things.<p>In a different life...<p>[1] <a href="https://news.ycombinator.com/item?id=29882347" rel="nofollow">https://news.ycombinator.com/item?id=29882347</a>
Recently I started to only work in daylight times, I had to shift my sleep 3-4 hours sooner. The idea is to never need to use artificial lights, wouldn't work well in high latitudes winters though :))
That's a pretty bold statement that nightlights are associated with obesity.<p>But there's a theory blue/white reduces melatonin output.<p>So, use red nightlights, apparently true red wavelengths don't affect sleep.<p><a href="https://www.healthline.com/health/why-not-to-have-red-lights-on-at-night" rel="nofollow">https://www.healthline.com/health/why-not-to-have-red-lights...</a>
Maybe related: Morning and Evening Blue-Enriched Light Exposure Alters Metabolic Function in Normal Weight Adults<p><a href="https://pubmed.ncbi.nlm.nih.gov/27191727/" rel="nofollow">https://pubmed.ncbi.nlm.nih.gov/27191727/</a>
What worries me is that some of the research done on this suggests that even tiny amounts of light could have a noticable effect, like green and blue LEDs on common home electronics when it sits in standby or sleep mode.