Does LED lighting count as a dodgy technology?

[scatterandfocus]

Admittedly, I do have a bias here, which has been developed through personal experiences with LED technologies.  The first experience that I can remember was with LED flashlights years ago.  No one wanted one of those things pointed at their eyes.  The reaction to LED flashlights was much stronger than with traditional filament flashlights.  The light from them was intense, very blue, and had lots of glare.  The same was true with LED headlights.  When those things came around, everyone complained about seeing them on the road.  It was uncomfortable to the eyes and blinding to everything else on the road when those things were coming at you in the opposite lane.  Then I got a laptop using LED backlighting, coming from a laptop that used a CFL backlit display and a desktop that used a CRT monitor.  I never had any issues with the latter, other than sometimes getting red and dry eyes from the CRT after spending long hours in front of it.  But within a year or two of using the LED backlit display, I got a wicked case of eye strain that physically made me feel sick, with aching eyes and feeling like I had the flu.  I never had eye strain before that point, so I didn't really understand what was going on.  After that, I got more cases of eye fatigue, but having experienced full-on eye strain, I knew enough to get away from the display before eye strain set in.  As the years rolled on, I began seeing lots of mentions of blue-light and PWM eye hazards related to LED displays.  And LED lighting became mainstream, followed by lots of people talking about feeling uncomfortable with LED lighting and potential hazards of LED lighting.  At some point it began to be more difficult and more expensive to find the same range of incandescent/halogen bulbs (and CFL bulbs looked bad to me), and I decided to try LED lighting at home.  But I still haven't found LED lighting that I feel comfortable with for reading and other tasks.  It seems ok for me in less critical areas, such as hallways and porches.  So yes, I do have a bias from these personal experiences with LED technologies.  But I am still willing to explore newer LED technologies to see if there is something out there which might work for me, because LED lighting has obvious benefits of power efficiency and potentially lower cost over time.

You once loosely connected two phenomena and since that time you see the perceived issue pop up in various places? That could be the textbook definition of confirmation bias. It sounds a lot like the people who suffer greatly from electromagnetic radiation from real and imaginary sources.

Meh.  I think my personal experiences go hand in hand with varous industries addressing the issues of LED.  Every major eyeglass lens manufacturer is making blue-light blocking lenses.  Every major monitor manufacturer is including blue-light reduction and flicker reduction technologies.  Every operating system is including blue-light reduction software.  Every major bulb manufacturer is making reduced blue-light reduced bulbs and flicker free bulbs.  And on and on.  And most of the industries are claiming to address eye-care issues, not sleep deprivation.  I guess these industries also have 'confirmation bias', and goes right along with my own and so many other people.

[Marco]

Flicker free bulbs were always available, the only thing which has changed is that all the shitty bulbs have now made it worth using it as a marketing bullet point.

As for the rest, yes the public is by and large irrational and the manufacturers will respond to that rationally. Give the people what they want ... they want super warm high CRI light sources with lousy lm/W, the market will provide.

[rrinker]

 Most new(er) devices including desktop operating systems and displays themselves, have a "night mode" which reduces the blue portion of the spectrum. If I am alone in the office at work, I keep the lights off over m area, and use the night mode on my displays. I use the night mode on my handheld devices almost constantly - I'm not doing photo editing where I need accurate colors, I want the easiest on the eye setting. Seems to help. I never noticed the one effect of the bluish light keeping me from sleeping at night, but especially in a darkened room, the night mode causes less eyestrain. This is not the same issue as the UV leaking out, but a bright white/bluish LED backlighting I would say definitely causes more eye strain than a more reddish hue.

[Kilrah]

I guess these industries also have 'confirmation bias', and goes right along with my own and so many other people.

They go with what people will buy, which makes them money. Whether people buy for a valid or completely made up/placebo reason doesn't matter.

[Mr. Scram]

Meh.  I think it goes personal experiences go hand in hand along with varous industries addressing the issues of LED.  Every major eyeglass lens manufacturer is making blue-light blocking lenses.  Every major monitor manufacturer is including blue-light reduction and flicker reduction technologies.  Every operating system is include blue-light reduction software.  Every major bulb manufacturer is making reduced blue-light reduced bulbs and flicker free bulbs.  And on and on.  And most of the industries are claiming to address eye-care issues, not sleep deprivation.  I guess these industries also have 'confirmation bias', and goes right along with my own and so many other people.

I appreciated how determined you are to dig the confirmation hole ever deeper.  Blue light concerns are about our bodies taking cues from colour temperatures and blue light messing with sleeping patterns as it is recognised as daylight. If blue light causes your perceived issues regular daylight should trigger it too.

[scatterandfocus]

Most new(er) devices including desktop operating systems and displays themselves, have a "night mode" which reduces the blue portion of the spectrum. If I am alone in the office at work, I keep the lights off over m area, and use the night mode on my displays. I use the night mode on my handheld devices almost constantly - I'm not doing photo editing where I need accurate colors, I want the easiest on the eye setting. Seems to help. I never noticed the one effect of the bluish light keeping me from sleeping at night, but especially in a darkened room, the night mode causes less eyestrain. This is not the same issue as the UV leaking out, but a bright white/bluish LED backlighting I would say definitely causes more eye strain than a more reddish hue.

Most display manufacturers include a 'Reader' mode which shifts the color balance toward a warmer white.     I think they aren't trying to put anyone to sleep while reading.  But yes, most operating systems do call it something like 'Night' mode.  But if you search for 'night mode' for any operating system, you will see most recommendations for using it mentioning preventing eye pain or eye strain.  This isn't an issue that I just made up out of thin air.  It is a very common and well discussed issue to do with computer displays since some years ago.

[scatterandfocus]

Meh.  I think it goes personal experiences go hand in hand along with varous industries addressing the issues of LED.  Every major eyeglass lens manufacturer is making blue-light blocking lenses.  Every major monitor manufacturer is including blue-light reduction and flicker reduction technologies.  Every operating system is include blue-light reduction software.  Every major bulb manufacturer is making reduced blue-light reduced bulbs and flicker free bulbs.  And on and on.  And most of the industries are claiming to address eye-care issues, not sleep deprivation.  I guess these industries also have 'confirmation bias', and goes right along with my own and so many other people.

I appreciated how determined you are to dig the confirmation hole ever deeper.  Blue light concerns are about our bodies taking cues from colour temperatures and blue light messing with sleeping patterns as it is recognised as daylight. If blue light causes your perceived issues regular daylight should trigger it too.

You sound like you want to argue with someone for the sake of arguing.  Carry on I suppose.    

[fourtytwo42]

I think with regard to dodgy LED lighting the OP may be thinking of a regular poster on this and other fora who's posts often contain the phrase "OUR CONTRACTOR"

Said posters subjects are nearly always related to an apparently dodgy company putting together dodgy LED lighting products based upon the advice of other members of various fora 

These products are apparently LED streetlamps so I would definitely avoid being anywhere near them 

[james_s]

Did you come here seeking information or is this another one of those posts we see occasionally where someone comes in to spout some conspiracy theory or other nonsense veiled as a question about the topic?

There is nothing dangerous or dodgy about LED lighting. Some is better than others, some can cause eye strain, but unless you are really trying by staring directly into a bright light source you're not going to actually damage your eyes. Blue light may well trigger your body to wake up when you should be preparing to sleep but that is not specific to LED.

[Buriedcode]

Meh.  I think my personal experiences go hand in hand with varous industries addressing the issues of LED.  Every major eyeglass lens manufacturer is making blue-light blocking lenses.  Every major monitor manufacturer is including blue-light reduction and flicker reduction technologies.  Every operating system is including blue-light reduction software.  Every major bulb manufacturer is making reduced blue-light reduced bulbs and flicker free bulbs.  And on and on.  And most of the industries are claiming to address eye-care issues, not sleep deprivation.  I guess these industries also have 'confirmation bias', and goes right along with my own and so many other people.

You must remember, the consumer industry doesn't always do things because there is good evidence for it.  Cosmetics and dietary supplements are good examples here - it is what consumers think they should do that drives the industry.  Unfortunately these ideas are used as evidence that it is valid, so it becomes a circular argument.  Banning a certain chemical from cosmetics, so advertisers can say "now without xyz" which leads people to assume its bad because - why else would they remove it?

The blue light thing, as far as I'm aware came about because of three semi-related things. 
Firstly, as LEDs got brighter, the amount of blue light coming from the cheaper higher colour temperature dies became significant.  This was mostly because of the brightness rather than the blue light itself, it is just unfiltered, there is a pretty strong blue line in white LED's, where-as the rest of the spectrum is spread out.   Modern white LED's tend to have a much less pronounced peak here.

Secondly, the discovery that we have cells in our eyes that seems to respond to blue light and are associated with circadian rhythms.  This is why you often read about "screen time and disturbed sleep".  I couldn't actually find any reasonable studies of this (please link if you found some) apart from news sites making claims.  It has been assumed but not confirmed that it actually disrupts sleep, because the few studies I found used "screen time" (which involves web browsing, reading, interacting) or blue light (which isn't what screens emit) rather than just a blank white LED backlight.  Here, someone has made the leap that blue light disrupts sleep -> white LED's emit blue light -> phone screens use white LED's as backlights (except the OLEDs!) ->  ergo, phone = bad sleep.

Thirdly, the relatively recent discovery that prolonged exposure to bright blue light can damage the eye.  Again, it seems the media has assumed that "blue light" means "any white LED source, because they emit blue.. right?".  It isn't really a fair test to expose retinal cells, in a dish, to strong blue single wavelength light, then assume that a phone screen will do the same to cells in the eye itself.  But thats not what was originally claimed.

I have no doubt that very bright LED sources can damage the eye, cause eye strain, and headaches.  But so can all other light sources if the intensity is sufficient.  I also don't know about the "blue light in white LED's affecting sleep" because I haven't found a reasonable study to actually test it.

One tip for the OP - turn the brightness down.  Most of the tablets, phones and laptops I've used over the past 10 years have become increasingly brighter on their default settings, significantly so. I recently set my phone brightness to 10% (Huawei TFT) and got used to it in about  a day.  At night, if I use it in low light levels I can get away with even lower that that.   Also, "night mode" is handy on some browsers, since many websites still insist on having white backgrounds.   If in doubt, don't change anything, and measure the light intensity yourself - then use those numbers for comparison when you reduce the brightness.

[NiHaoMike]

"Reduced blue light" is just marketing speak for "warm white".

As for screen flicker, wouldn't there be more complaints back when 60Hz CRTs were the norm? Modern LCDs that flicker do so at 120Hz or more in order to reduce motion blur by hiding the times when the pixels are transitioning. (In 3D mode, that gets cut to 60Hz by the glasses which does flicker quite bad. Hence why 240Hz is a common target for high end 3D displays, giving a very acceptable 120Hz in 3D mode.)

[james_s]

CRT phosphors have a bit of persistence that helps but even so I could never tolerate 60Hz refresh, I always used 72-75Hz. LED backlights with PWM dimming often bother me much more.

[Kilrah]

Fluorescent lamps have flickered more than a decently designed LED lamp for decades and people were OK with that...

[james_s]

Fluorescent phosphors also have some persistance, more so than LEDs so that could come into play. I was not bothered by fluorescent lamps and most LED lighting doesn't bother me but the stuff that flickers at line frequency does. It feels like a much more sharp strobing than the flicker of old iron ballast fluorescent lights.

[coppice]

Fluorescent phosphors also have some persistance, more so than LEDs so that could come into play. I was not bothered by fluorescent lamps and most LED lighting doesn't bother me but the stuff that flickers at line frequency does. It feels like a much more sharp strobing than the flicker of old iron ballast fluorescent lights.

The phosphors used in fluorescent tubes and LEDs have very little persistence. When either of these lamps is driven directly from the mains cycles, and you follow their light output through the mains cycles, they go pretty much down to zero output 100 or 120 times a second.

[james_s]

Fluorescent phosphors also have some persistance, more so than LEDs so that could come into play. I was not bothered by fluorescent lamps and most LED lighting doesn't bother me but the stuff that flickers at line frequency does. It feels like a much more sharp strobing than the flicker of old iron ballast fluorescent lights.

The phosphors used in fluorescent tubes and LEDs have very little persistence. When either of these lamps is driven directly from the mains cycles, and you follow their light output through the mains cycles, they go pretty much down to zero output 100 or 120 times a second.

Perhaps the LEDs go down to zero through a larger portion of the cycle? I don't know, I haven't actually measured. I just know that I can very much see the flicker on some LED bulbs while most others are just fine and don't visibly flicker at all. I've always bought one to evaluate first before buying more if I like the one I got.

[coppice]

Fluorescent phosphors also have some persistance, more so than LEDs so that could come into play. I was not bothered by fluorescent lamps and most LED lighting doesn't bother me but the stuff that flickers at line frequency does. It feels like a much more sharp strobing than the flicker of old iron ballast fluorescent lights.

The phosphors used in fluorescent tubes and LEDs have very little persistence. When either of these lamps is driven directly from the mains cycles, and you follow their light output through the mains cycles, they go pretty much down to zero output 100 or 120 times a second.

Perhaps the LEDs go down to zero through a larger portion of the cycle? I don't know, I haven't actually measured. I just know that I can very much see the flicker on some LED bulbs while most others are just fine and don't visibly flicker at all. I've always bought one to evaluate first before buying more if I like the one I got.

Some LED lamps are certainly off for a significant part of the cycle, as they won't turn on until the voltage has risen far from zero, so this may be a factor. Don't discount the effects of size. Most LED lamps have a much more intense output, as their radiating area is small. That intensity seems to affect how much a light source appears to pulse. Hopefully we will move away from screw in LEDs, towards structures with more space for better control electronics, and the flicker will go away.

[maginnovision]

I'd love to have some LED sconces all in one units.

[james_s]

They make them.

I think that is the future of LED lighting, obviously retrofit lamps will be widely available for the foreseeable future but I'm confident that we will see more and more integrated light fixtures with no user replaceable parts. It will result in a lot of completely new light fixture designs that do not need to be built around the form factors of available lamps. Most of the lighting in newly built homes and commercial structures will be integrated LED designs rather than incandescent or fluorescent fixtures with LED lamps, it's already going that way.

[coppice]

I'd love to have some LED sconces all in one units.

There are a lot of these around, especially for designs introducing interesting form factors. Some are great, like large flat units for kitchen ceilings, that really spread the light out, and minimise shadows. The snag is they aren't designed to be user serviceable, and the parts don't follow standards, so they are hard to exchange. Hopefully this will change, but right now most failures require complete replacement, and a physically identical unit will probably not be available when you need one.

[maginnovision]

They're also fairly dim from my limited searching right now. In my office I use two sconces and each one has two 2500 lumen 5000K triglow led bulbs. Pretty sure none that I've seen will be able to light this room well enough. I'll have to keep looking.

[Electro Detective]

To avoid the possibility of copping a 'dodgy technology'    financial hit,
I'm sorta going old school and asap losing the 'previous dodgy technology' crappy circular fluoro light in the kitchen (dim, buzzing, hypnotic disco light, random RCD tripping POS  ) 

and getting a similar shaped fitting, that takes a pair of standard (buy anywhere/CHEAP) ES screw or BC bayonet LEDs in a warm white vibe, 10+ watts each,

covered over with an aesthetics friendly oyster styled diffuser.

A fitting like this I could care less about a 12 month replacement warranty offered with the latest integrated LED units that apparently 'last a long time..'
which is hard to believe as they haven't been around a 'long time' yet 

My choice above will 'last a long time' based on sheer simplicity, redundancy (2 LEDs), easy swap out, simple fault diagnosis
and heaps cheaper to buy and a simple quick swap out for our local sparky to grab some cash on his/her way home 
If LEDs become dodgy technology, I can always chuck in a pair of 60 watt old school light globes, till the next 'technology' come along.

I've already dumped those annoying squiggly and tubular shaped light savers
and replaced with nicer LEDs 

Light fittings should be seen and not heard,
or something like that   

 

[james_s]

I did some quick tests tonight using a small PV cell connected to a scope and got some actual data, because engineers love data. This is not perfect, I was lazy so I didn't worry too much about ambient light but it remained constant throughout the test and was not a major contributor. I corrected for it in the first shot and then stopped doing that so for the generic integrated LED fixture use your imagination to add about a 1V DC offset.

Anyway despite the flaws I still think this is interesting. Of the random light sources I had laying around the cheap integrated LED fixture is the only one that I noted to exhibit bothersome strobing and the resulting waveform illustrates why this is, the light output falls sharply to near zero where it spends a significant portion of each cycle before snapping on to nearly full brightness. Somewhere I have some LED filament bulbs that behave very similarly and I've seen a lot of low cost domestic LED fixtures that do the same. It is unusual in that the driver it uses is linear, there are no reactive components. The fluorescent lamp which is an older tube with a halophosphate type daylight phosphor on a simple choke ballast has nice smooth 120Hz bumps in the light output but doesn't fall to anywhere near zero between cycles. The other lamps have a bit of either 120Hz or high frequency ripple but no visible flicker. The amplitude was low enough that the frequency measurement on the scope can't really be trusted and I didn't feel like fussing around to capture that since it has no visible effect that I can see anyway.

I can further investigate the properties of any of these various sources later if anyone is interested.

[scatterandfocus]

Well it is good to see that at least some discussion happened.

How I see it, the reason why LED's end up causing eye strain and eye fatigue (especially in displays) is that they have a strong blue component (even edging on ultraviolet)l, intensity of the overall light, and PWM dimming.  People who don't understand this often say that turning down the brightness of a display should be good enough.  Well, it really isn't.  One reason that merely turning down the brightness doesn't often work is  because displays use PWM dimming, which tires the eyes.  At full brightness, a PWM dimmed display can actually be easier on the eyes, especially if it isn't a very bright display to begin with, because at full brightness the backlight is steady.  But manufacturers were in a race for ever brighter displays (and still are to some degree), neverminding the negative effects of PWM when these super bright displays are dimmed.  As someone mentioned above, CRT's did flicker at low frequencies, but there was also a smoothing effect involved, rather than a sharp-edged off/on flicker.  LED's respond very fast, and so the effects of PWM can be much harder on the eyes.  Manufacturers have been addressing this by pushing the PWM frequency far up and calling their monitors flicker-free.  Well, at least we don't see the flicker, but some of us can still feel the uncomfortable effects of it.  And combine that with the strong blue component of LED displays, and it's not a good situation for eye comfort and eye health.  Blue light having a shorter wave length than the rest of the visible spectrum is more easily able to penetrate the eyes.  This isn't the same situation with sunlight because there isn't a huge dip just below the blue spectrum with sunlight as there is with LED, and the top of the red spectrum isn't suddenly chopped off as it is with LED light.  Also, LED and other natural light aren't nearly as diffused as natural light, and LED in particular can have a hard glare to it, along with the heavy blue component and along with the PWM.  Also, the strong blue light spectrum is very much analogous to listening to loud high frequencies.  And PWM dimming is very analogous to listening to square waves, where there is a high frequency switching taking place that is in addition to the high frequency blue light spectrum.  Neither are a pleasant experience, for the eyes or the ears.  Oddly, some people seem less bothered by it all.

Something that I have found in my experience of trying to continue to use computers regularly since LED backlighting became the norm is that VA panels are actually somewhat easier on the eyes than other display types.  It isn't perfect, but it is more comfortable.  I think this has to do with VA panels being capable of blocking more of the backlight (VA panels typically have much greater contrast) and VA panel pixels having significantly slower response times that TN, IPS, or OLED, which may  be smoothing the on/off switching of the LED backlight.

Any way, whether anyone here agrees with it or not, some people (aye!) have been permanently affected by LED backlighting, for whatever reasons.  And once that happens, our eyes become more sensitive to LED lighting in general.   It's a repetitive stress injury, the same as any other, where the eyes have been worked too hard.  Getting away from LED lighting altogether definitely does help, but in the long run it is impractical.   There is no conspiracy here.  I'm here to discuss electronics issues the same as anyone else.  I have no motives other than learning from and adding to the collective wisdom of members of a forum, the same as any other forum.

[Electro Detective]

No contest to the above OP comment   

That said, if you want products that are 'easier' on the eyes, you have to shop around and try what's on offer till you hit on a goodie,
and don't lose those purchase receipts 

Not all LED lights, monitors, plasma displays, CRT products etc are equal in quality or how one's eyes perceive the images

i.e. been there already