Very interesting. I've always thought that there was something a bit "off" about LED torches and car headlamps; the brightness is there, but something about the light just doesn't seem to illuminate as well as an old dim incandescent or even fluorescent tube.
It's usually the Color Rendering Index (the spectrum of frequencies that the light puts out). Incandescent bulbs more of less mimic that of the Sun, they are "black body radiators". Cheap LEDs tend to be missing a lot of the red spectrum.
However, you can get LEDs that do this well. Look for one with a "CRI" of 95% or higher.
Yes lots of them use cheap LEDs with poor CRI, high color temperature, and a huge blue spike in the spectrum. All of that leads to a very bright looking light that also doesn't let you see detail very well.
I have incandescent light bulbs at home I have to pretty much smuggle from China. It's amazing how we're replaying the asbestos playbook a century later. Only this time it's government mandated.
Why is it that right now there is still on the frontpage of an "article being found flawed after 6k citations " ( https://statmodeling.stat.columbia.edu/2026/01/22/aking/ ) but this random article coming out of nowhere makes the front page on the same day?
People really should get it and stop sharing newly published papers to the general public. The value of one single academic paper is exactly 0. Even a handful of such articles still has 0 value to the general public. This is only of interest to other academics (or labs, countries, etc.) who may have the power to reproduce it in a controlled environment.
Be very skeptical of correlations like this that have dubious or poorly understood causation. Be even more skeptical if they are about day-to-day stuff that would likely have large swaths of people able to reproduce something like it on huge scales yet they haven't. Extraordinary claims require extraordinary evidence.
This article is not making an extraordinary claim, and your offence is hyperbolic. Analysis of research should not be restricted to the academe, but careful not to cherry puck research.
No mention of CRI which seems kind of odd. LEDs for lighting are increasingly graded by how natural their emission spectrum is. Older lights are quite bad, newer ones sacrifice a tiny bit of performance for more uniform spectrum.
What is the relationship between CRI and how broad (or narrow) the spectrum output by the LED is? Is CRI automatically better for broader-spectrum LEDs? Or is that too simplistic?
Just to point to anybody that comes here directly, the article has no relation at all with perceived illumination, color fidelity, or anything else people complain about leds.
It's an interesting niche topic that you may want your working place to notice if you work indoors.
There is a 15-30% difference between the groups at baseline (fig 8c-9c, 8d-9d), about the same magnitude as the claimed effect of the experimental condition.
I think the result would be much stronger if these baselines were comparable, so they show they have accounted for other variables like time of day and light history. I am also skeptical of any effect in the retina lasting 6 weeks, with no fading.
Consider that people are often exposed to much more infrared light outdoors, so "worked under a relatively dim incandescent lamp" is not a particularly novel stimulus. Imagine that any of these people spent time outdoors during the six weeks - thousands of times more infrared light there.
I've been using incandescent more often. All my vanity lights are 40w appliance bulbs now. The difference at night is remarkable. The LED is just too much even at 2700k. I still prefer LED for high power situations like br30/40 can lights.
Was just discussing last week with a colleague how for the same 'lumen' there was such a dramatic difference between led and incandescent bulbs for ease of reading paper books.
Yes, there is something obviously wrong with most LED lights, but it isn't too much of short wavelength light, but on the contrary. It's the near absence of cyan light in most LEDs. Our eyes are by far the most sensitive to it, the majority of receptors in the eye are sensitive to it, and we may focus primarily on it (focus differs for different wavelengths). This is how you get the feeling of something being wrong with your vision as you for example walk into a mall, and so on.
If anything, higher temperature lights seem to make it better, not worse, but the problem will persist as long as the cyan hole stays there.
It should be noted that even if we assume that the conclusion of this study is correct, i.e. that artificial lighting should have a wide spectrum including near-infrared light, that does not mean that returning to classic incandescent lamps is the right solution for this problem.
The incandescent lamps with tungsten filaments have a much lower temperature than the Sun, thus much more energy is radiated in infrared than needed.
There was about a year or two ago a discussion about a very interesting research paper that reported results from testing an improved kind of incandescent lamp, with energy efficiency and lifetime comparable to the LED lamps.
The high energy efficiency was achieved by enclosing the lamp in a reflecting surface, which prevented energy loss by radiation, except for a window that let light out, which was frequency-selective, so only visible light got out, while infrared stayed inside. The lamp used a carbon filament in an environment that prevented the evaporation of the filament.
With such a lamp, one can make a tradeoff between energy efficiency and the content of healthy near infrared light, by a judicious choice of the frequency cutoff for the window through which light exits the lamp.
Even with enough near-infrared light, the efficiency should be a few times higher than for classic incandescent lamps, though not as good as for LED lamps. Presumably, one could reach an efficiency similar to that of the compact fluorescent lamps (which was about half of that of LED lamps), for such an incandescent lamp that also provides near-infrared light.
I found some interesting tidbit about this bigger issue. And I want to share how to more easily check it.
We many times see some people reporting that they clearly see lower quality LED light flicker and is really distracting to them and even causes them headaches.
Now, I didn't see this until recently (unless in failing lights) in the right conditions. If the light is very, very dim: For instance, only 1 light on in the night, and you are in a division far away from the light so that it's extremely dim. There, I could finally really see it flicker.
I've replaced that light for a better one and the effect went away.
Scientific Reports is a junk journal fyi. Not conclusive, but indicative.
Despite saying the visible flux component is "small" and that the tungsten lamps "were not expected to [be used] as task lamps," Figure 6 (a) and (c) shows... desk lamps right at the work stations like task lamps! Not only is this experimentally unblinded, but the visible light immediately in front of the test subjects is noticeably brighter and warmer. The effect could simply be due to reduced eye strain.
What would James Randi do? "Extraordinary claims require extraordinary proof," and unfortunately this isn't it.
This would be more interesting if they add a visible light filter on the lamps so they only emit infrared radiation, and have an identical double-blind control with a 60 watt heater bulb so it emits no SWIR but the same radiant heat (which could confound and/or unblind).
The push toward LED seems to be primarily for emission target related reasons. It is very hard to buy incandescent bulbs in the UK; even for those of us that accept the cost implications. Also, many less expensive LEDs flicker at the rate of the frequency supply of the current (ie 240 or 120 Hz). This is very annoying and related to the instantaneous response of LED vs the averaging effect of the alternating current through an actual glowing hot filament. It is interesting to read on the development of blue and white LED technology.
This should also be true for TL lights. Which kinda contradicts common sense seeing that those are used all over the place in offices, kitchens, and hospitals, makes me think this paper is bogus.
There are some full spectrum led lights, they just cost over $100 a piece. And they might get banned in the future for not being energy efficient enough.
I hate the LED street lamps so much. I can tell they've got a really spiky and unnatural spectrum, unlike the HPS lights, not to mention that they're white or bright yellow...
I’ve always been mildly bothered by the LED lighting in my home, as if it’s simultaneously bright but not illuminating. In simple consumer terms, if I wanted to shop for a variant that more closely replicated incandescent lighting, what exactly am I looking for on the packaging? Or does this not exist?
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[ 0.22 ms ] story [ 88.8 ms ] threadHowever, you can get LEDs that do this well. Look for one with a "CRI" of 95% or higher.
People really should get it and stop sharing newly published papers to the general public. The value of one single academic paper is exactly 0. Even a handful of such articles still has 0 value to the general public. This is only of interest to other academics (or labs, countries, etc.) who may have the power to reproduce it in a controlled environment.
Be very skeptical of correlations like this that have dubious or poorly understood causation. Be even more skeptical if they are about day-to-day stuff that would likely have large swaths of people able to reproduce something like it on huge scales yet they haven't. Extraordinary claims require extraordinary evidence.
It's an interesting niche topic that you may want your working place to notice if you work indoors.
I think the result would be much stronger if these baselines were comparable, so they show they have accounted for other variables like time of day and light history. I am also skeptical of any effect in the retina lasting 6 weeks, with no fading.
Consider that people are often exposed to much more infrared light outdoors, so "worked under a relatively dim incandescent lamp" is not a particularly novel stimulus. Imagine that any of these people spent time outdoors during the six weeks - thousands of times more infrared light there.
Yes, there is something obviously wrong with most LED lights, but it isn't too much of short wavelength light, but on the contrary. It's the near absence of cyan light in most LEDs. Our eyes are by far the most sensitive to it, the majority of receptors in the eye are sensitive to it, and we may focus primarily on it (focus differs for different wavelengths). This is how you get the feeling of something being wrong with your vision as you for example walk into a mall, and so on.
If anything, higher temperature lights seem to make it better, not worse, but the problem will persist as long as the cyan hole stays there.
The incandescent lamps with tungsten filaments have a much lower temperature than the Sun, thus much more energy is radiated in infrared than needed.
There was about a year or two ago a discussion about a very interesting research paper that reported results from testing an improved kind of incandescent lamp, with energy efficiency and lifetime comparable to the LED lamps.
The high energy efficiency was achieved by enclosing the lamp in a reflecting surface, which prevented energy loss by radiation, except for a window that let light out, which was frequency-selective, so only visible light got out, while infrared stayed inside. The lamp used a carbon filament in an environment that prevented the evaporation of the filament.
With such a lamp, one can make a tradeoff between energy efficiency and the content of healthy near infrared light, by a judicious choice of the frequency cutoff for the window through which light exits the lamp.
Even with enough near-infrared light, the efficiency should be a few times higher than for classic incandescent lamps, though not as good as for LED lamps. Presumably, one could reach an efficiency similar to that of the compact fluorescent lamps (which was about half of that of LED lamps), for such an incandescent lamp that also provides near-infrared light.
We many times see some people reporting that they clearly see lower quality LED light flicker and is really distracting to them and even causes them headaches.
Now, I didn't see this until recently (unless in failing lights) in the right conditions. If the light is very, very dim: For instance, only 1 light on in the night, and you are in a division far away from the light so that it's extremely dim. There, I could finally really see it flicker.
I've replaced that light for a better one and the effect went away.
Despite saying the visible flux component is "small" and that the tungsten lamps "were not expected to [be used] as task lamps," Figure 6 (a) and (c) shows... desk lamps right at the work stations like task lamps! Not only is this experimentally unblinded, but the visible light immediately in front of the test subjects is noticeably brighter and warmer. The effect could simply be due to reduced eye strain.
What would James Randi do? "Extraordinary claims require extraordinary proof," and unfortunately this isn't it.
This would be more interesting if they add a visible light filter on the lamps so they only emit infrared radiation, and have an identical double-blind control with a 60 watt heater bulb so it emits no SWIR but the same radiant heat (which could confound and/or unblind).
Ban on all fluorescent tubes (T5 and T8 lamps) from August 24, 2023
Ban on all CFL lamps from February 24, 2023
Extension of the exemption granted to HPD lamps from 3 to 5 years
Extension of the exemption for special purpose lamps from 3 to 5 years
there may be more light (photons) but their spectrum is too limited for my eyes to see like halogen, etc.
I still only use compact florescent in my home, led is useless to me
That seems remarkable and almost too good to be true?