Anecdotal evidence to the contrary - i have a sunshine-bright light fixture at home (600W worth of metal halide arc lamps), and while it does make the dull winter days less dark and gray, it also tend to make me tire quicker.
It's the same sort of feeling you get when you haven't slept in a while after having slept too much - your brain still feel fine, but your eyes are already tired (and yes, i checked the lamps for a lack of UV).
I'm assuming you've never spent a winter somewhere with less than 3 hours of daylight during the winter months. I don't think anyone who has would question the effect of sunlight on mood.
When I lived such a winter, the effect of standing in full sunlight when it was available was like eating sugar after heavy exercise. (And biochemically, this makes perfect sense given that we know the body uses sunlight to synthesize essential compounds.)
It makes sense to question the effect of a specific lamp, but the body's need for sunlight is obvious, even absent the scientific research.
So these are UV bulbs? I know bright light is used to combat SAD, but AFAIK that's not about vitamin D, just the light itself having an effect on mood.
No idea; the effect seems similar but I do prefer the real sunlight for some reason. The lamp has the advantage of being easier from a time-management perspective though; I don't actually have to stop working and so on to use it.
But I don't think that attitude is conductive to point B; taking extra care with work-life balance, getting enough exercise and decompression and so on, so I have a low threshold of just dropping what I'm doing and taking a break in the daylight :)
You seem convinced your brain "slows down" after the equinox due to (the lack of) bright light, but it's probably just the placebo effect. Has anyone ever convincingly measured the effect of bright light therapy on mood and intelligence?
Do you have any more resources to read up more on these effects? After working in a windowless office I've started to notice some psychological issues with the lack of sunlight, especially during the winter, and with what you're saying I'm starting to wonder if the problems are worse than I'm even realizing.
Even on a cloudy winter day the sun's luminocity is about 20 times higher than a very bright phone display.
My point is that it is not reasonable to assume a strong physical reaction if the artifical light is so much weaker.
Note I'm not denying that there isn't a small effect! But it is probably dwarved in comparison to a change in eating habits, anti stress methods like meditation, sports and so on.
> It's 100% a fact that blue light is the light which impact the production of melatonin the most, and that melatonin directly regulate your circadian rhythm.
Then why don't most studies study effects on the actual circadian rhythm? My guess is because the results there are less clear with actual sleep (i.e. they actually studied both but only published the "good" results - a sad side effect of publication bias).
BTW the same is true for light therapy for prevention of winter depression: There probably is an effect, but it is so weak that rigorous meta analysises don't show real evidence.
My overall point is: There seldom are strong effects with most treatments of this kind. If there were, we already would have found out in pre science times. People are doing artifical lighting for thousands of years (think campfires, not LED lights).
I have a neurological disorder called visual snow syndrome that's the root cause, nobody really understands where it comes from but the current theory is a dysfunction of metabolism in part of the visual cortex. It causes all sorts of weird visual stuff like the eponymous 'tv snow' and other distortions as well as intractable headaches, apparently it has similarities with certain kinds of migraine. As for the photophobia it's quite a difficult sensation to describe but for me its acute form is an unusual sensation that's in the same category as pain without being pain itself - it's like the sensation of looking directly at the sun but with ordinary light sources that don't bother other people. The chronic form is less intense, it basically just makes concentrating in a bright environment exhausting after a while and it trashes my focus, making me headachy and irritable. As a result I never have strong lights on even at night, and I also don't drive in the dark because the glare from the headlights can mess up my vision for minutes at a time which is obviously not safe.
Fluorescent tubes are among the worst offenders for messing with my concentration, though anything with a pronounced 50 Hz flicker or too high a colour temperature isn't great for me. The kind of cheap lights offices traditionally use are particularly bad which is part of why I'm full time WFH now!
Tangentially related: I've been experimenting with very bright lights from when I wake up to sunset. In my bedroom/home office I have a couple 6000k LED lights at 8100 lumens making the room almost as bright as noon outdoors. Post-sunset I use dim red lights. I was inspired by SAD lights but didn't like any of the ones I tried so went with high-powered "corn" LED lights in normal fixtures.
I've noticed that I tend to get sleepier at night which is great as before I would have to force myself to go to sleep (I'm a natural night person.)
I've also noticed a small increase in my distance visual acuity (subjectively measured by me using an eye chart so not the most accurate.) I have read that intense outdoor light protects against myopia (see https://www.ncbi.nlm.nih.gov/books/NBK470669/) so I suspect this is related.
Not sure about the science here, but I have found the opposite to be true for me. I love natural light and crave it while I work. However, I have found that if the room is just a little too bright I will end up with severe eye strain and headaches after a day of work. Ambient light is the unfortunate cause.
Previous research has shown that light exposure increases alertness, but this is one of the first studies to pinpoint how it influences the human brain at the neural level. I'll be outside if you need me.
I agree, but AFAIK the most common symptom is amplified “visual snow”. While everyone has some level of visual snow, an increased amount such that it’s visible during the day/on bright surfaces would certainly be annoying
> bonus points for the children eyesight falacy, as studies already proved its mostly caused by reading/studing long hours in poor light.
Nothing to do with reading or studying (i.e. "eye strain"); it's purely the poor light.
Facts for fun, from what studies I've read on the subject:
Photosensitive retinal ganglion cells produce dopamine when they're struck with daylight-like light levels; this dopamine affects the flexion of the musculature around the eye, which in turn affects the shape of the eye as the eye, those muscles, and the bones of the skull all develop and grow together (the muscle under flexion "reserves" more space for itself, so less is filled with bone, and so, when relaxed, it allows the eyeball to expand.)
The human body has evolved to assume this effect, and so the eyeball develops into a "normal" shape only under the presence of this chronic photo-mediated local dopamine release. Without it, the eye develops into a more ellipsoidal shape, distorting the cornea.
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One thing I haven't been able to glean from these studies is what light level qualifies as "daylight-like." Do the photosensitive RGCs activate only under full sunlight (~100K lux); with shaded sunlight (~10K lux); on overcast days (~1K lux)?
My own hypothesis is that the limit lies somewhere between "shade" and "overcast", since a lack of photosensitive RGC stimulation leading to a lack of SCN-mediated dopamine release to the brain generally, is a good explanation for Seasonal Affective Disorder; and—more anecdotally—the symptoms of Seasonal Affective Disorder seem to me to line up with the common experience of living in regions of the world with persistent overcast weather (e.g. London, Seattle/Vancouver, Tokyo.) I'd love to see a study of whether those regions have higher-than-normal levels of nearsightedness in the populations that grew up there (though this effect might be totally invisible next to larger effects like differing choices in indoor/outdoor activities for children.)
SAD is one of those things where I've read articles and research from what I think are at least semi trustworthy sources both swearing that it is a real thing and that it is not a real thing.
Anecdotally it seems like a scam to try and sell you overpriced LED lights, but the more you google the more you find some people swear it affects them, even though I've never felt the difference. This together with the fact that I was born and grew up in a place with ~3050 average annual sunlight hours per year, as well as lived in places with ~1500 for the past 5 years without any perceived difference in mood.
Bright lights give me a headache, especially in midday when it's bright outside. I'll often resort to wearing sunglasses indoors when it gets out of hand.
Perhaps it's a certain kind of light, but I don't get the same kind of headache outside in bright lights. (Although I do find bright days painful.)
I'll echo this, I had similar results restricting blue light.
What clued me in was when I went camping for a weekend after not camping for almost a decade. I found myself falling asleep and waking early, feeling better, even after a single night, and it got even better the second. Real darkness after sunset, and tons of bright sunlight in the morning.
Wearing the goggles IS a pain though. Worth it but a pain. F.lux didn't do nearly enough in my experience though it does seem to have an effect.
I also find that sunrise simulator clock is okay for waking up but not strong enough to replace bright light exposure in the morning. I would recommend eating breakfast outside in the sun for awhile, and if you find that helps, get some lights with some heavy duty lux for the winter mornings inside.
Anecdotal evidence to the contrary - i have a sunshine-bright light fixture at home (600W worth of metal halide arc lamps), and while it does make the dull winter days less dark and gray, it also tend to make me tire quicker.
It's the same sort of feeling you get when you haven't slept in a while after having slept too much - your brain still feel fine, but your eyes are already tired (and yes, i checked the lamps for a lack of UV).
Perhaps it is a question of a dose...
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