The American Medical Association is concerned that the glare, the high blue light content of “energy efficient” LED streetlights being rolled out across America, might be suppressing drivers’ night vision, and causing other harmful health effects.
AMA Adopts Community Guidance to Reduce the Harmful Human and Environmental Effects of High Intensity Street Lighting
For immediate release:
June 14, 2016
CHICAGO – Strong arguments exist for overhauling the lighting systems on U.S. roadways with light emitting diodes (LED), but conversions to improper LED technology can have adverse consequences. In response, physicians at the Annual Meeting of the American Medical Association (AMA) today adopted guidance for communities on selecting among LED lighting options to minimize potential harmful human and environmental effects.
Converting conventional street light to energy efficient LED lighting leads to cost and energy savings, and a lower reliance on fossil-based fuels. Approximately 10 percent of existing U.S. street lighting has been converted to solid state LED technology, with efforts underway to accelerate this conversion.
“Despite the energy efficiency benefits, some LED lights are harmful when used as street lighting,” AMA Board Member Maya A. Babu, M.D., M.B.A. “The new AMA guidance encourages proper attention to optimal design and engineering features when converting to LED lighting that minimize detrimental health and environmental effects.”
High-intensity LED lighting designs emit a large amount of blue light that appears white to the naked eye and create worse nighttime glare than conventional lighting. Discomfort and disability from intense, blue-rich LED lighting can decrease visual acuity and safety, resulting in concerns and creating a road hazard.
In addition to its impact on drivers, blue-rich LED streetlights operate at a wavelength that most adversely suppresses melatonin during night. It is estimated that white LED lamps have five times greater impact on circadian sleep rhythms than conventional street lamps. Recent large surveys found that brighter residential nighttime lighting is associated with reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning and obesity.
The detrimental effects of high-intensity LED lighting are not limited to humans. Excessive outdoor lighting disrupts many species that need a dark environment. For instance, poorly designed LED lighting disorients some bird, insect, turtle and fish species, and U.S. national parks have adopted optimal lighting designs and practices that minimize the effects of light pollution on the environment.
Recognizing the detrimental effects of poorly-designed, high-intensity LED lighting, the AMA encourages communities to minimize and control blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare. The AMA recommends an intensity threshold for optimal LED lighting that minimizes blue-rich light. The AMA also recommends all LED lighting should be properly shielded to minimize glare and detrimental human health and environmental effects, and consideration should be given to utilize the ability of LED lighting to be dimmed for off-peak time periods.
The guidance adopted today by grassroots physicians who comprise the AMA’s policy-making body strengthens the AMA’s policy stand against light pollution and public awareness of the adverse health and environmental effects of pervasive nighttime lighting.
###
Media Contact:
AMA Media and Editorial
Pressroom: (312) 239-4991
Email: media@ama-assn.org
Read more: http://www.ama-assn.org/ama/pub/news/news/2016/2016-06-14-community-guidance-street-lighting.page
Perhaps city authorities were so eager to embrace “energy efficiency”, they never took the time to check whether their new green street lighting systems were safe.
..The law of unintended consequences…the bane of the liberal left ideas !
LED lights also save money.
Saving money is not a liberal left idea.
Unless of course, should this study be legitimately credible, the attendant consequences to health and safety become economically untenable and end up costing more overall.
there, fixed it for you!
Perhaps they should shift from the higher intensity Blue-White LED lighting to a lesser intensity yellow color light
“Perhaps they should shift from the higher intensity Blue-White LED lighting to a lesser intensity yellow color light”
Actually, if the primary purpose of the color shift is to preserve driver / pedestrian night vision, red light should be used.
Amateur astronomers use red lights for reading reference material and equipment dials because the red light does not affect night vision.
They renovated one of the main roads here last year and indeed installed red street lights, I was wondering why, but night vision may be the answer…
Wife had insomnia, now I have $100 of LED bulbs in a drawer
https://chiefio.wordpress.com/2012/07/22/superchiasmatic-led-light-insomnia/
I also now use yellow ‘sun’ glasses at night when driving so I can see better. The blue bright headlights and streetlights are a menace and reduce visibilty due to glare.
“The whole modern world has divided itself into Conservatives and Progressives.
The business of Progressives is to go on making mistakes.
The business of the Conservatives is to prevent the mistakes from being corrected.” –
Illustrated London News (ILN), 4/19/24
Chesterton
Things never change with progressives.
That is awesome!
But mikerestin, I hope you’re not implying relevance to today’s, American, “conservatives.” Not only are American “conservatives” more like the classical liberals of J. S. Mill than royalist, aristocratic, stuffy and propertied English “Conservatives,” but the News was writing about 1924, for Pete’s sake, almost a century ago, and – although verbally cute – I have no idea what the author actually had in mind as an example of this Conservative behavior.
Of course Progressives have not changed and they continue to go on making mistakes.
It’s just a play on words, Jeffrey . . Like; Liberals beat dead horses . . and Conservatives defend them (said by me, as a US teen in the late sixties ; )
Progress is good . . if it is good progress (freshly coined)
Jeffrey June 27, 2016 at 3:36 pm
The fact is the identical issues have been current for a very long time. Who gets to say what is acceptable and who must conform:
http://www.poetryloverspage.com/poets/kipling/macdonoughs_song.html
It hasn’t changed yet. Chesterton was “conservative” in the current sense, but he was also in some ways a cynic and used that as a fuel for humour. The message is clear, some are always trying to make things “better” and just as often failing. Their opposition opposes them to the point that nothing does get fixed. Consider the close relationship between Romneycare and Obamacare. Will either ever be fixed? Not likely.
Clever is not the same as true.
Do any of their ideas NOT have unintended consequences??? And they keep getting away with it. No wonder they hate personal responsibility.
Oh those nasty “they”, at it again. By “they” do you mean the world’s powerful, greedy elite? Like the owners of large media conglomerates and fossil fuel empires and their shock-jock henchmen and right-wing echo-chamber think-tanks and propagandist bloggers?
Wow, so many stereotypes. So little actual thought.
You sir have managed to portray your average socialist perfectly. Congratulations.
Does anyone know of any Green ideology (or idea) that worked? Does anyone know of any Green politician or alarmist who accepts personal responsibility? That I happen to think THEY are Watermelons means I’m talking about socialists too. Yes.
You got a clue why communism/socialism has never worked out the way THEY intended? They never deliver on their promises. They don’t know how to. The people don’t win under communism/socialism. They lose.
I knew there was a reason why I hate those LED head lights on some new cars. They are too blue.
Hugely dangerous, as I am very sensitive to glare when driving at night, and these headlamps make me shield my eyes.
Then wear a light shade of sunglasses. It reduces almost all glare with only a tiny reduction in overall vision.
Tom, okay, Mr. Corey Hart. Great idea to wear sunglasses while driving.
*at night.
I drive with amber coloured glasses. They eliminate glare
Steve you are right. The amber sunglasses have had advertisements for night time glare. they work well.
Agree. More blue light means the guy you meet is blinded by your lights. The older I get the harder it gets to keep the car between the ditch and the moving spotlight.
Not all people have perfectly adapting eyes, yet we as everyone depend on driving. I wish my lights would adapt by increasing power when needed.
In 1970 I bought a new car, an Audi, which apparently was one of the first with the high intensity blue lights. While on low beam setting I was pulled over at night by a State cop. I showed him what the high beam was like and he just shook his head.
Dan Kurt
When flying at night I used a red filter on my flash lamp also the instruments were red lit in order to prevent glare. Wearing amber tinted glasses is also effective.
Those are high-intensity discharge (HID) headlights, not LED’s. They use an electric arc discharging through a gas, e.g. mercury and sodium vapor lights. Same problem, though, too blue. Warmer colors don’t glare as much, which is why fog lights are yellow and IR telescopes can see through interstellar dust.
Once upon a while ago, they couldn’t get blue from an LED, and it was a problem. You need red, green, and blue to make white light, so they had to use thin fluorescent tubes to backlight your thin-panel computer displays – high voltage, more heat, less efficient. No blue cut LED’s from most other illumination chores, too.
The fellows who finally solved the blue LED problem won the Nobel prize in 2014.
Many headlights are now true LED. And LED drop-in replacement lamps are available for almost all headlights.
That is right Mike. The statement from the AMA is stupid and they obviously don’t know that the mercury vapour lights the LED’s are replacing are also heavily biased to the blue end of the spectrum. The mercury vapour lights were in use for more than 40 years so why haven’t we heard about this blue spectrum thingy before? I don’t even want to think about the worse than useless high pressure sodium lights they have been using for the last 20 years or so.
Regarding Matt Bergin’s comment on the strong blue spectral content from mercury vapor light: Its wavelength is 435.9 nm, which is fairly efficient at stimulating blue cones, but much less efficient than most other blue wavelengths for stimulating the melatonin-related receptor, or for that matter rods that are responsible for scotopic vision. Notably, a clear high pressure mercury lamp with color temp. around 6000-6500 K has scotopic/photopic ratio like that of an incandescent whose color temp. is a little on the warm side of typical at 2600 K. A phosphored mercury lamp with nominal color temp of 3900-4100 K has s/p ratio like that of a dimmed incandescent or a long-life low wattage incandescent nightlight with color temp. of 2300 K. For the melatonin-related receptor, high pressure mercury vapor is about as stimulating as an equal photometric quantity of incandescent lighting with color temp. around or not much over 2700 K..
I just shopped for LED light bulbs, they now come in different color “temperatures”, just like incandescents have for some time. This is an easily solvable problem, if a problem it really is. Given the source of the complaint, and their history, I reserve judgement. I.e., I want the claim checked.
I think the obnoxious headlights are Zenon HID lights. The blue color makes night look like day to the driver, but that’s no reason to blind oncoming traffic. Modern LEDs are dimmable and come in different color temps. Some have adjustable color temp. No reason that self dimming and self aiming cannot be as common as power windows.
I started using LED lights at home for apps that need a ladder to change and wear out often. I’m happy with the new ones. CREE is a US LED company that makes most components in the US. Top quality stuff.
A friend has a Tesla and it is a remarkable car if you want to spend $100k on a hot car, electric motors are already superior to conventional, except for the batteries which need development work. Half the price and twice the miles would be quite competitive. I think they will survive without the subsidy.
Greenies are generally nutty as fruitcakes, but there is some good coming from this mess.
The law of unintended consequences strikes again. The focus should be saving money, not saving energy.
No, the focus should be lighting the road without blinding drivers and/or pedestrians.
Cost would be an added benefit but making the roads more dangerous by bad lighting or partially blinding drivers will soon wipe out any savings in LED efficiency. The traditional mercury or sodium arc lights are already quite efficient : we’re not comparing to incandescent bulbs !
My town ( southern France ) has installed LED street lighting and it is physically painful to look at. You need to walk with your head down in the evenings.
This may just be bad design rather than an inavoidable concequence of LEDs but it needs to be looked at before rushing ahead due to the usual “save the planet” crap.
It is bad design, in two parts. One is using LEDs of a color that is more blue-rich than available 2700K (incandescent-like), 3000K (halogen-like) and 3500K (moonlight-like). The other part is using the efficiency gain to greatly increase lighting level at the expense of achieving great energy savings. Many lighting installation planners seem to think that the electric bill of the fixtures being replaced was tolerable and therefore does not need to be decreased much.
The biggest money savings will be in labor.
LED lights won’t need to be replaced anywhere near as often as other types.
DLK … compared to sunlight of approximately 6500K
Regarding Streetcred’s claim that sunlight’s color temp. is 6500 K: It is 5875 K before it hits Earth’s atmosphere and is lower afterwards. In my experience in and near Philadelphia, average direct sunlight is around 4400 K around noontime and less at other times of the day. 4100 K is designed to simulate the color of typical direct sunlight.
Kodak designed color slide film to render colors properly when the light source has color temp. of 5500 K. Apparently, this is a typical color temp. of sunlight and skylight combined. Overcast skies have a higher color temperature for some reason, possibly because liquid water and ice are not perfectly colorless but slightly bluish. However, I find overcast skies are usually less bluish than light sources said to have a color temp. of 6500 K.
Am I the only one that thought the very yellow glare of low pressure sodium lights was pretty horrible as well. Particularly with wet roads the yellow street lights actually seemed to hide the road markers making it difficult to see the lines. They seemed to test the lights usability in only optimal conditions.
I don’t have enough experience with the new LED lights to compare them yet. I am impressed with how well they control the ‘spill’ of the light which helps prevent light pollution. I’m not sure if the AMA is misinformed on that issue or if their concern is cheaper lighting means more lighting.
No, you’re not the only one, although I think the LP Sodium lamps are an improvement over the painful, glaring, color altering, blue/violet mercury vapor lamps they often replaced. Sadly, the most comfortable outdoor lighting seems to be the good old fashioned, power hungry, broad spectrum Edison incandescent lamps.
I don’t understand why we need so much all-night, outdoor lighting to begin with. Your car’s headlights are on, right? On the back roads that seems to be plenty safe. “Security” lighting is an oxymoron–it just shows the would-be burglars where to go to break in! I’ve had a chat with all my neighbors about killing their outside lights completely once they’re in for the night–and after hearing why, they DO it!
Dear Goldrider,
Ask any police officer: light prevents crime.
Also, while some lighting may be overkill, indeed, my experience last year in a California city (after the generally excellent roads (the roads, both in design and in maintenance, in CA are shockingly bad) and lighting in my home state of Washington) with bare-minimum street lighting was that it is VERY hard to read street signs or see people crossing the street (not all people are perfectly rational street crossers, you know). Why must we live with “bare minimum” lighting (where it is helpful)? This is America, not some poor, third world, country where they are just struggling to make it… Is it? Hm.
Finally, re: the HTNH’s (Hate-thy-neighbor headlights) – Why not do what is loving? There are many people whose night vision is ruined and who struggle to drive at night because of those headlights. I do not have this problem, but I hate how they assault my eyes with their over-bright glare. Every time I see them I think: why? Just to be cool, you poke your neighbors in the eye? Yeah. That’s very cool – not.
So, I agree that sometimes, lighting is overdone, but, I would rather err on the side of safety and comfort.
Janice
— so I flash my high beams at them. I know it is illegal to do that. I do it anyway.
Janice … “This is America, not some poor, third world, country where they are just struggling to make it… Is it? Hm.”
Given the Clinton potential, in 4 years time the mighty USA may be lucky to be “some poor, third world, country”. 😉
Hi, Streetcred — Yes, indeed. That horror of a candidate MUST be defeated! Aaaa! And no “wink” about it — she is truly twisted and bent on doing harm. #(:|)
Janice, the street light/crime issue is not a simple one:
http://www.citylab.com/housing/2014/02/street-lights-and-crime-seemingly-endless-debate/8359/
The sad fact is that no one knows. In some places improved light does seem to correspond to lower crime, but in other areas, it can actually correlate to increased crime. In many there seems to be no change in rate corresponding to changes in lighting (up or down for either crime or lighting). There’s no neat tidy answer unfortunately. It seems to depend upon community and sociological factors.
We probably have better success forecasting weather.
The pole our yard light, a 175W mercury vapor yard light, was mounted to rotted and fell over in a wind storm. We replaced it with a 32W LED on the pole-barn. the led seems to illuminated more, but is a little bit harsh and glaring. I haven’t noticed it effecting my nightvision one way or the other.
Slightly OT. I recently replaced our security lighting of 10 x 80W mercury vapour lamps with 10 x 14 W white light LED’s. The result was better security lighting and a 70% reduction in our electricity bills.
I think the concern, at least a proper concern, is mostly about the quantity of light. I have found LED streetlight retrofits being done in a way that boosts the illumination level excessively. If the illumination level is increased less, there is less hazard and energy savings are greater.
Too bad the AMA cannot really be trusted. Still, there may be something to this. Perhaps selecting lower “temperature” LEDs is the answer.
The AMA represents only about 25% of physicians.
When a Doctor graduates, they get a sheepskin and a 1 year free AMA membership. According to my brother (a family practice physician), most doctors never renew. From that anecdotal report, I wonder if maybe a third of the membership is just-graduated free-riders.
The answer is simple. Use tricolour LED panels, red green blue as on your TV display, and each lamp can be factory color adjusted to whatever are required for best visual acuity and safety.
Most TVs use blue LEDs with “white” phosphors that don’t create much green or red, so they have to turn up the blue intensity and throw away a lot of blue, yellow, and orange which is produced but not needed, and still to get enough green and red, the color filters have to be set quite wide resulting in a low color gambit.
Not only would having tricolour LED panels allow you to adjust your color spectrum for specific requirements, it would pave the way for lighting that could adjust ON THE FLY to adapt to changing conditions. Foggy? More yellow for better viability. Heavy rain? Greener for better penitration. Late at night? Red for better night vision. There could even be a ‘Police/Emergency’ mode where they can be switched to extra bright blue-white when needed.
I would have thought that the characteristics of the light cover might come into play. It would be understandable if they are going for maximum illumination but given the downside of that they may want to strike a balance with glare and directionality. LED’s have too many advantages to give up on easily. The biggest is actually long life. given the labour costs for changeouts this is important.
Long life is the biggie. Low pressure sodium is actually way more efficient (about 2x) than LEDs (but LEDs are catching up). The place where LEDs could actually do much better is if they turned them off or dimmed them when not needed. Ideally the LED light fixtures could sense when there are no cars present and dim themselves accordingly. LP sodium has a horrific startup time and can’t do this efficiently.
The LED color for street lighting could be more natural, but the LEDs working at these color spectrums are not yet very efficient compared to the harsher blue/white LEDs.
As for Brewster’s comments that LPS is more efficient than LED: LED has now caught up, although 200-205 lumen/watt LED streetlights (not counting ballast losses, same as for 180 lumens/watt for the most efficient wattage of LPS) are probably only a year or two away. 180-185 probably a year at most.
All the new Law Enforcement Cars with the new LED flashing lights along with Fire Trucks are VERY dangerous. At night when they have pulled over someone and they leave the lights flashing it is extremely hard to focus on the road. A Danger to all. Double that with the glare of rain splashed roads.
Am I the only one with this problem?
No, your not. The problem is that in order to gain attention the lights are inordinately bright, but it’s contrast against the background that makes things obvious, not intensity. It’s sort of like Spinal Tap, by turning everything up to 11 you could no longer hear the music, you could only hear the noise.
Additionally, there’s no good reason to make your eyes process information across the entire spectrum, (blue to red to blue to red). A combination of blue and orange strobes is enough of a contrast, but cops have been using red for so long there’s a lot of push-back to the change
Orange/Yellow is already used in most areas for caution/utility vehicles. Red is standard for ALL the emergency vehicles like fire and EMS. In most areas I’m familiar with blue by itself is used for volunteer fire or DNR (lake cops and rangers). The police have the red/blue combo exclusively and guard the privilege. They want everyone who sees that combination to know right away who they are.
Now, you COULD change the colors to something a bit less glaring. Personally I’d keep the red and change the blue to green. But the red/blue combo is traditional by now and isn’t likely to be changed, if only because everyone already knows what it means. It’s the blue that causes the most trouble though, and if it’s just there for identification purposes then it doesn’t NEED to be at full attention grabbing intensity. The Red lights already do that. The best choice may be to tone the blue down to about half the brightness of the red then. Identification maintained and passers by unblinded.
There should be a dimmer on those LEDs when the vehicles are not in motion. Drivers are dazzled as they pass an accident scene or driver that has been pulled over. Sometimes it is difficult to see the person directing traffic due to the LEDs being too bright.
No you are not the only one, I find it makes on blind to other things happening on the road. No need to be so bright in my mind.
Indeed you are not. The very short wavelength blue flash is irritatingly difficult to see through.
Exactly same effect on me.
Not alone. In California in the 60s the police and fire used red only. It worked fine.
Now, driving out of State, there are these red blue blinding things by the roadside that are a positive hazard. I can’t see a darned thing driving past them and just have to hope I’m in my lane and not driving over a cop.
Using yellow ‘sun’ glasses at night helps, but really, I have to put on sunglasses at night? This is better how? More light is not better. More visibility is better. Under a full moon with lights out I see better than on a freeway with LED streetlights and blinding cops strobes…
I’m partially blind in both eyes so the LED street lights don’t bother me when I’m driving.
😉
I have always wondered how many accidents are caused by people who refuse to wear eye correction because they are too cheap/lazy or (ugh) have “nerd” syndrome for glasses. Amazing how someone will run into an interstate roadside parked car at night with the tail lights on, possibly because they think it’s in the driving lane and can’t tell because their uncorrected vision is so bad.
H.R., thankfully they have braille at the drive up ATM windows.
lol
That’s not a joke, there really is braille to use “for the visually impaired” at the drive up ATM.
Okay, Tom. I was focusing on the “drive” part — apparently, they anticipate blind people walking up to those ATM’s (or getting out of a car driven by a sighted person and walking over to the ATM) to use them.
Sorry to have laughed at what you meant to be taken quite seriously. Yes, it is good that there is Braille available. Not laughing about that.
No Janice, I think it is hilarious that the government requires these kinds of notices. These drive up ATMs are not for walk ups and you should not get out of the car. They are drive up only. It is ridiculously funny but sadly true.
At my current bank, there is no longer an ATM in the lobby. The only ATM is the drive through ATM, which yes, has Braille on the keys. The keys are no longer recessed or shielded (probably because such measures are not ADA friendly) so I always feel very exposed when I am using it. I am probably just paranoid, but I have visions of someone watching to get my PIN and then coming up to my car and demanding my card (or car). Even if that is unlikely, the fact is that these “accessible” features lower security for everyone else.
The other annoying part is being stuck waiting in the drive thru lane to use the ATM. Waste of gas and time. I would rather park and wait in the lobby behind a couple people than sit in my car for 10 minutes. People are faster inside!
Tom in Florida & Janice –
http://joke-king.com/wp-content/uploads/2015/01/No-left-turn-only-right-turn-too-Funny-Pictures.jpg
Oh, I think that Braille on drive-up ATM’s was done for ADA compliance.
H.R. — laugh — out — loud. And just beyond that, no doubt, is a “SLOW CHILDREN” sign.
Tom, once we have real self-driving cars, then Braille at an ATM will make sense.
I like LED tech. I actively choose the cooler, more incandescent colors. The CFBs were a disaster.
LED lights are so inexpensive to operate, I lust leave them on all the time.
The blue lights are bothersome.
Leaving them on might be good for life also as with other types of lighting, it’s the number of start cycles that does them in.
LED lights have essentially no wear from starting. Also, most incandescents don’t suffer significant wear from starting, but become unable to survive a cold start a little before they become unable to survive continuous operation. Many incandescent lamp life extenders that smooth out cold starts also dim them enough to account for most of the life extension, and efficiency of incandescents is reduced by dimming them.
With incandescents the start up stress was from the rapid warming.
With fluorescent (both long tube and curly) the start up stress was in the circuits that increased the voltage from 120 to about 400 Vs need to get current to start flowing in the tubes.
LEDs don’t have either of these problems.
LEDs need DC, but at a lower voltage than the 120V (~180V RMS) line voltage.
Step down power supplies tend to be more robust.
The life of the LED is pretty much determined by the junction temperature, which in turn is almost solely dependent on the current through it. (The rest is determined by the LEDs ability to dump heat to the environment.)
A couple of LEDs driven hard, won’t last as long as more LEDs with lower average current through them.
Wasn’t talking about the LED proper but the power supply surge current on starting (although there are probably better surge protection on some brands). Once the power supply is dead, there goes the unit. Might explain early failures on some units.
Regarding what MarkW said: The reason most fluorescents suffer wear from starts is actually from the filaments conducting current to the arc when they have not yet warmed up enough for proper thermionic emission, so they suffer ion bombardment. As for rapid temperature rise of incandescent filaments killing them, that is usually not the problem – but uneven temperature rise of a cold filament being hard-started. A filament that has suffered uneven evaporation has its thinner area(s) having a temperature overshoot during a cold start. That is caused by uneven filament evaporation, and the unevenness has a positive feedback that means a filament’s hours are numbered after it becomes so unevenly evaporated that it becomes unable to survive a cold start.
Next-gen LED lamps mitigate nearly all of the issues that murdered older gen lamps, and come at a siginficantly reduced cost if you know where to get them. I bought a bunch from China during a refresh of my home’s light fixtures.
These, in fact, for about $2 a piece:
To get an equivalent brightness of these in the UK would cost £10 or more. At the time I bought them that would have been about $14.
They put out barely any heat, have a much nicer lighting profile than CFL and – crucially for me – they don’t flicker. I can see the flicker in most CFL bulbs. Gives me a headache.
My biggest complaint regarding LEDs is that at least in my area they only come in output equivalents of 40Ws and up. (Sorry, I grew up with incandescents for over 40 years, so when talking brightness I will always compare to incandescents.)
I have a number of multi-bulb fixtures that produce an adequate about of light with just 40 to 60Ws. As a result I only put one bulb in them and leave the others empty.
Can’t someone make some 15 and 20W equivalent bulbs? I’d buy them.
Regarding availability of LED light bulbs that are less bright than 40W-incandescent-equivalent: They are widely available at major name home centers. Sadly, in my experience they cost more than general-service 40W-equiv. and 60W-equiv. LED light bulbs.
Not mentioned but certainly relevant is the spot concentration of the light source. HID (high intensity discharge) headlights, LED’s without diffusers, and arc welders all have extremely concentrated light sources dangerous to your retina. The old style sealed beam headlight distributed the light source across about 9 inches of glass and while annoying at night wasn’t a complete disaster to your night vision. The new HID lamps are only a couple of inches across, higher power, and often lean toward blue in the spectrum. I have to hold up a hand and shield my eyes from that kind.
I wish that polarizers had been mandated for headlights.
LED car lamps are if anything worse than Xenon-arc bulbs for wrecking night-vision. And as those bicycle flashing headlights!
I should like to see additional lamps mounted under the car that shineoutwards,sideways and down, to illuminate the adjacent roadway for oncoming traffic. This should help those who are dazzled by these over-bright lights.
Incidentally, having observed a couple of actual roadkills, [which apparently is a rarely observed event in comparison to the number of kills]…. this could also reduce the amount of slaughter on the roads. Why? Because it would reduce the impulse of animals to launch themselves, as the headlamp beam passes, into the dark area behind, but straight into the parth of the unlit rear-wheels.
We’ve had a lot of “upgrades” in the area over the last 2 years, and it always appears to me that the “new and improved” lights make it impossible to see beyond the intersection. It’s the same as walking into a building after being outside on a sunny day, (or just the opposite). The local D.o.T. engineers dispute my claim, and counter that they went to a “seminar” on the topic. I guess they must be right, how would I know? since I only spent 3 years post-doc studying visual information processing problems for a large D.o.D. contractor.
Astros outfielders have a lot of trouble with the new lights at Minute Maid Park.
I was thinking the same about Tropicana Field in Tampa but it is the players who suck not the lighting.
Some things never change.
I will relate my personal experience regarding blue light. I attended college in the early 80s. My dorm room had fluorescent lights at each desk and dresser and a regular incandescent light on the ceiling. I took some clear acetate sheets and using permanent markers made some colored tubes to put over the fluorescent bulbs. Blue, green, orange and red. The red and orange went over teh dressers. The green and blue went over the desks.
I found that the greenish light was easy on the eyes and made reading very comfortable. Not so for the blue light. Eye strain and headaches occurred if I used the blue light for reading.
I agree on the green vs blue. I tend to see farther and more clearly at night with green.
I also noticed there isn’t a tendency for after glow from a bright green light.
As for turtles, I know from experience the effect of a bluish white light on them vs an orange/yellow light. Having had 14 sea turtle nests emerge at once and all the babies headed toward the kitchen light left on instead of the ocean. That was a mess and took me almost all damn day to track and clean it up. Nesting beaches are banned from high intensity blue lighting and require orange street lights. Residents on those beaches are prohibited from leaving any light that isn’t orange on that might spill onto the beach or be seen from the beach during nesting season.
Talk about burying the lede. Blue light at night does more than affect melatonin levels, it confuses the body into thinking the sun is still shining and a host of hormones you need for good health that are produced in your body at night either aren’t produced in sufficient quantity or aren’t produced at all. Circadian rhythms are hugely important for good health and blue light at night significantly alter them.
Blue light is found in more than just street lights – TVs, tablets, computers, phones all produce blue light and the exposure will lead to poor health over time. I run a program on my computer that eliminates blue light from my screen – download at https://justgetflux.com/
Thanks!!!
Great program – I’ve used f.lux for years. I do almost all of my reading on the iPad Kindle app and always use white letters on the black background – much easier on the eyes and little problem falling asleep. And red acetate over the clock radio blue numerals is great for the bedside. Photographic gels are perfect for this.
Hopefully LED technology improves to let us dial in what feels and looks the best. But for general lighting, it’s hard to beat the look of good old incandescent.
True white has light wavelengths in equal amounts accross the entire visual spectrum. LED ‘white’ has 3 predominant wavelengths that appear white to the human eye. No matter how bright this kind of light is, it does not reveal as much detail as a true white light.
For LEDs white light is generally produced by combining blue light (450 +/- nm) with a phosphor that produces orange/red by absorbing the blue. By varying the amount of phosphor any color temp between ~6500 and 2500 k can be produced. I suspect that the cheapest to produce and most efficient are the higher color temps. Thus we are stuck w/ annoying “blue” lights because of cost and efficiency.
Good point regarding the phosphor. However see this wiki article
https://en.wikipedia.org/wiki/Light-emitting_diode#Phosphor-based_LEDs
As can be seen, the light is still very heavy on the blue.
They do have “tunable” LEDs that have 4 leads, three colors and ground.
These are often used for specialty lighting.
I’ve never priced them so I don’t know how much the cost.
Stage productions like them because they make those overhead spotlights smaller/lighter and they don’t heat up the on stage talent the way the older incandescents used to do.
Most white LEDs have a spectrum with a blue spike and a broad band from mid-green to somewhere in the red. That band is broader in versions with higher color rendering index, extending from bluish green through into deep red.
The ambulance chasers will be hot on this trail.
I have yet to find an LED that does not feel a bit irritating to the eye compared to other lighting types.
I’ve been using LED headlamps and flashlights for mountaineering and ultra running ever since the tech came out about 15 years ago. There have been huge improvements in the “color” and output, along with lower cost, over that time. The phosphor conversion is getting better all the time and I would bet that before too long we will have emitters that emulate blackbody radiation pretty well. I’ve added a couple LED shop lights in my garage and I like them a lot more than the T14 fluorescents I’m using.
There are already 2700 and 3000 K LEDs with color rendering index of 97. They can be found by using the search tool at Digi-Key.
I believe you, but for cost and output reasons I doubt they are being used for massive lighting like street lights, yet. But coming…
The earlier high output “white” emitters were “squid piss” tinted.
O.T…..More corruption of science at the EPA !!
“This clearly violates the law and makes a mockery of the notion of ‘independent’ scientific review,” Energy and Environment Legal Institute General Counsel Steve Milloy said.
http://www.foxnews.com/science/2016/06/27/epa-panel-backs-tough-new-ozone-regs-after-getting-200m-in-grants-lawsuit-charges.html?intcmp=hpbt2
To preserve night vision, red led light works well, It’s been used by people using telescopes for decades, the other spectrums all kill night vision, with blue being the worse.
Micro..
You are absolutely correct, all marine Compasses use red light so that it does not destroy the night vision when trying to see everything in the water. This has been known for years, why has it been overlooked in modern lighting?
Red is an effective color for general nighttime illumination such as streetlighting for two reasons. It has less photometric content per watt of emitted light than white, green, yellow or orange light. It also has even more greatly less ability to stimulate scotopic vision than white, green, yellow or orange light. The lack of scotopic stimulation is why red light has very low impact on night vision. Scotopic vision is significant in streetlighting, even though photopic vision is also functioning. Red lights are used at night to be seen rather than for illumination, or to illuminate small areas.
Mike Crow and Cat Cracking,
Yes, indeed, in pilot houses of ships red lighting is essential, so that the pilot’s night vision isn’t ruined (they run with a dark pilot house at night). Not much illumination, however, as (I think) Mr. Klipstein is talking about. So, good for “mood” lighting, and pilot houses (and telescope rooms, and the like), but not going to work for driving more than 5 miles per hour, heh.
Nice that the old time car manufacturers were thinking people. RED tail lights… 🙂
Did I say red was “effective” for streetlighting due to low lumens per watt of emitted light and low scotopic stimulation? That is a typo of mine – I was trying to say why red lights are *ineffective* for streetlighting-type illumination.
Well, they’re not interested in whether the lights are safe, they just want to save the world. /sarc.
^^This.^^
It is not just the direct beam from LED signal lights that seem disturbing, but the reflection of wet roads has the same characteristics, whether due to narrow spectral output or the laser-like coherence and polarization of the beam perhaps. Visit the now LED dominated lighting section at Home Depot, particularly the motion detector lamps and you can “feel the burn” as they flick on.
Once CFLs have been designated as hazardous waste and we have replaced with LEDs (I estimate $2000 for my apartment) we can move on to the next generation of “nanophotonic incandescents” which promise efficiencies more than twice that of LEDs with, (hopefully) a return to a more eye friendly spectral balance.
http://news.mit.edu/2016/nanophotonic-incandescent-light-bulbs-0111
For years, truckers have used blue light to keep them alert. link
It looks to me like we have a trade-off. Alert drivers will reduce accidents. Vision impared drivers will increase accidents. We don’t know which will predominate.
Recent large surveys found that brighter residential nighttime lightingA diet high in carbohydrate (and alcohol) is associated with reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning and obesity.fixed
I’ve warned about this for years. But apparently a counter argument is that it’s good for pedestrian safety because of the better colour rendering of LED lights, so clothing with the wrong colours wont appear as dark.
Where I live there is frequently fog and a visibility around 50m during winter limiting the speed to 30-40 km/h. If they replace the sodium lamps with LED here, the effect will be very bad. The monochromatic properties of sodium lamps work well in fog whereas white LED light will just create a white wall below the lamp in heavy fog. There are many reasons why white/blue LED lights are such a bad idea.
The flip side is that lighting with a heavy blue component is especially problematic with regard to dark sky light pollution, while the hideous yellow LPS lighting gets high marks from those trying to preserve dark sky conditions. You can’t please everyone.
Sodium light, whether the usual high pressure or the even-worse low pressure, has a drawback for illumination – many reds, greens and blues appear darker than they do under the same illumination by other light sources. And as for illuminating fog: I think LED lights only need to have scotopic/photopic ratio no higher than that of incandescent / halogen car headlights, and that is the case for most white LEDs with color temperature 3500 K or less. Scotopic/photopic ratio is the main nighttime factor for illuminating fog. Fog reflects by Mie scattering (wavelength-independent) rather than Rayliegh scattering (wavelength-dependent), so shorter wavelengths are only worse by increasing s/p ratio.
It is important to note that the message wasn’t “don’t use them” but instead “don’t be stupid about it and install extra bright ‘daylight’ balanced light engines”. That’s a huge difference. AMA’s concerns are addressed in their recommendations that LED light engines be no higher CCT than 2700k with a maximum brightness (which I don’t remember). They also noted to make sure emission of blue light was limited as they claim it is possible for a 2700k LED to still produce more blue light than a 2700k incandescent bulb.
I think it is important for the credibility of this website to tell the whole story and not straight bash all energy saving technologies including electric cars. We need to be able to say to the purveyors of DOOM that we believe they are full of S#!* but that doesn’t stop us from being responsible consumers of natural resources. Reduce Reuse Recycle is absolutely appropriate no matter what you believe about CO2’s effect on a habitable planet and I think WUWT should post in greater quantity positive stories about businesses municipalities and individuals who are conserving energy and other resources for the right reasons (not CO2).
Maybe WUWT could have a weekly or so article which highlights individuals who’ve changed their lifestyle or some aspect of how they heat/light/cool their home or travel to and from work. The focus should be on how their lives are better and how much money they’ve saved rather than their supposed impact on the environment. That is the kind of spin I’d like to see here.
And of course, please continue to post science that refutes the consensus and point out the hypocrisy that is evident in the accepted climate science community.
The blue emissions of 2700K LEDs generally stimulates scotopic vision and the melatonin-relevant photoreceptors a little less than the blue emissions of incandescents. The blue spike of white LEDs is generally concentrated to a peak around 450 nm to maximize efficiency of stimulating the blue cones (photopic vision receptors), so that a smaller percentage of the spectral content can be blue light (which has low photometric efficiency) and a larger percentage can be at wavelengths from mid-green to orangish red where the human photopic function is high.
Electric cars are not an energy saving technology.
Like Anthony who runs the site and has an electric car and solar panels on his house?
Dear Abram,
1. What is a “responsible consumer[] of natural resources?”
2. Re: Reduce Reuse Recycle is absolutely appropriate no matter what. Why?
What would a responsible user of coal have done in the 1700’s?
What would a responsible user of petroleum have done in the 1930’s?
What would a responsible user of copper have done in the 1960’s?
If they had followed your advice, they would have crippled their economies, resulting in poverty, misery, and death to millions. So, too, would the current batch of Malthusians who would have us cripple our economies by using unreliable, permanently negative ROI, wind and grossly inadequate solar, today. Fools who promote solar or wind power for powering an entire ECONOMY need to be soundly refuted, here on WUWT. India kicked Greenpeace out of the country for promoting such nonsense.
WUWT (and its commenters as a whole) have never condemned individual choice (paid for with private funds) to use solar power or wind for personal use. While many of us would not make the same choice, we respect their liberty to do so. As MarkW points out, our wonderful host, Anthony Watts, is one example of a home solar power user and electric car owner.
There is no need to conserve ANYTHING. Price, when allowed to operate in a free market, will guide our power buying choices.
You are promoting a philosophical view, not science realism, when you urge conservation per se. A Roman Catholic would be shouted off the thread if he or she were to urge everyone here to take a vow of poverty in order to become more holy. You are doing no differently, except that your religion does not require a Deity.
Why do you need ALL of us to follow YOUR faith? What is the crux of the matter? If I were to promote my own faith, I would answer, “the salvation of your eternal soul; your eternal destiny.” What is your BIG thing? What makes you so fervently urge us to follow your philosophy? In short, please answer re: conservation (of “energy and other resources”) for its own sake, “Why?”
You have not convinced this non-follower of your “way.” Not one iota.
My tone was blunt, for I see your philosophy as being very harmful to the health and happiness and freedom of other human beings. At least, for all my hard words, you can now see that you need to present a WHOLE lot more evidence if you want to persuade us to join you in your Rules for Living Responsibly. So! The floor (or should I say, “pulpit?”) is yours, O Abram.
Janice
“As chilemike points out … Anthony Watts…” (I beg your pardon Mike)
For years I’ve been pointing out that todays garbage dumps could easily end up being tomorrows resource centers. Things put into dumps don’t disappear (OK, maybe the organics do, very slowly) they will still be there tomorrow, a decade from now, 100 years from now. If our great great grand children decide that it makes economic sense to dig into those dumps to retrieve the iron, copper, whatever, they will be able to.
You do know Mr. Watts drives an electric car? What?, no? Oh, well, perhaps some contrition for leaping off a cliff of conclusion is in order…
Hey, you try UK streets with no lighting where the local government can’t afford the electricity bills any more where I have accidents just while walking along cycle paths at night. Thank you greenpeace
Funny thing is, the new fangled LED bulbs don’t seem to be leading to the local government switching the light back on. Could that be because they are not as cost efficient as existing technology for people who cannot afford a large capital outlay, or the greens have simply managed to destroy a “public good” with their policies?
Here’s another question: For self-driving cars, are their sensors better suited to any particular part of the light spectrum?
I’ve learned that some municipalities have been suffering from vandalism/theft of their street lights. I’m hearing that thieves especially like the copper. Municipalities are apparently refusing to repair their vandalized street lights, since they would only be vandalized again. Some curvy expressways through the center of town strike me as particularly harrowing to drive on at night without working street lights.
I changed all my interior lights to LED – energy cost saving was but one reason – LED bulbs basically last forever – I am tired of the continual need to replace bulbs. Especially in ceiling fixtures – changing them strikes me as far more dangerous than living under lED lights. They also produce no heat, making them “Use anywhere” bulbs. They can’t burn anyone, either. Or start a fire. LED Xmas trees would probably save many lives.
While LED lights are 4-5 times more efficient than incandescent lamps, they most certainly DO produce heat. Adequate cooling of the semiconductor die is a very important design consideration for LED lamps.
These LED lights are harmless and produce substantial energy savings when properly chosen and used. They are available in incandescent-like 2700, halogen-like 3000 and moonlight-like 3500 K color temperatures as well as more-blue-rich higher ones.
The problem is from using this technology excessively for increase of illumination, by obtaining more light and by obtaining a spectrum more-rich in mid-blue to mid-green wavelengths that are more visible to human scotopic (night) vision – which significantly affects apparent illumination by streetlighting in the usual mesopic vision conditions, where both scotopic and photopic vision are significant.
Here is a good article on effects of Blue light.
http://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
Send in the over priced, over subsidized, self-driving cars, with ambulance chasers
I know blue light from some “modern” vehicle headlights screw up my nite vision coming at me. PERHAPS I’ve noticed the latest headlights, thankfully, have abandoned the blue tendency & are more like the old. It’s been known forever that blue light screws up nite vision and I don’t know why those “blue” headlights were ever allowed. Red rear lights on vehicles are red for a reason….
The article omitted many benefits of LED street lighting that substantially offset the negatives mentioned in the article. Apparent light and visibility can be increased at lower energy costs. Optics can be used in almost any type of application to focus the light and reduce glare to a far greater degree than with conventional lamps. “Visual acuity” just should not be an issue. My company provided lighting for the new east span of the Oakland Bay bridge. The roadway lighting fixtures point AWAY from the drivers to eliminate most glare. As for residential use, proper optics and shielding for LED lighting SHOULD allow for very sharp “cutoff” of light so far less of it “spills” into the surrounding area compared to traditional street lighting. Looking at before and after pictures dramatically demonstrates the degree to which this can be achieved. In most cases there is thus no reason for it to be affecting local residents unless it is poorly designed. (Roadway lighting is not a market emphasis for us. We have, however, done some important architectural lighting projects where achieving very sharp cutoff/low spill is beneficial for the surrounding environment including, for example, Mount Rushmore.)
Years ago I lived in one of the few cities lit by gaslight: South Orange, NJ. We were so proud of this, a gas lamp was our village’s logo!
It is like walking round in soft moonlight, quite attractive. Yet peaceful. A slight warm glow.
Gaslights using light only from flames has color temperature generally in the low-mid 2000s, a little higher than the actual flame temperature because the emissivity of sub-micrometer or around-1-micrometer carbon particles is to some extent, even if only partial, related to Rayleigh scattering. Gaslights with mantles have color temperature generally in the low 3000s to around 3500 K and often a little more greenish than blackbody.
Somewhat related, LED traffic lights (green, yellow, red) become invisible when covered by snow, unlike incandescent bulbs LED’s don’t generate enough heat to melt any snow blown onto them, a real safety problem.
I noticed that too. I have seen on E-Bay that some LED headlights are now being sold that contain heating elements in the lens similar to a modern cars rear window defroster.
This should be fixable with a thermostatically controlled heating element.
I remember reading a few articles about this being a problem for municipalities in northern states. I would imagine that manual clearing would be necessary in places where temperatures remain below freezing.
I do not know if any of the lights in my area have been switched to LEDs, but there are some newer ones that look “different”, for lack of a better word. I personally think they are harder to see/differentiate (when another traffic light is a bit beyond the first), but I have no idea if it is a different design or if it is the bulb. The newest light replacement I have seen now has pure black backgrounds rather than yellow. I do not think I will like it in the dark.
I’m sure that if the AMA existed when street lights were first installed they would’ve complained about people’s night vision being destroyed.
It is well known that the left captured the AMA generations ago.
Dan Kurt
The LED streetlights i have seen have all been a huge improvement compared to the previos high pressure mercury and high/low pressure sodium street lights:
Higher and more uniform illuminance helps you spot pedestrians on a much longer distance and help pedestrians spot whatever lurks ahead earlier too.
Thats what streetlights are for!
Staring at them can affect you night vision and I beleive them when they say you can set up a lab experiment showing bluish white LED light is worse then yellowish white LED for “circadian sleep rythms”. But unless you have a particular powerful streetlight shinig at your window and you don’t use blinds, is it likely to be a problem for the residents?
I advice using the most efficient LEDs (Bluish White) in large and efficient reflector system. Some glare yes but the lowest cost for a given illumination spec. . By all means, if you have money to burn spend them on AMA lighting consultants and designer luminaires.
Off topic but only slightly. We’ve got quite a few LED lights in our house and the new ones have a nice spectrum that is somewhere between a regular incandescent and a halogen bulb. Big improvements in the last few years.
These lamps produce heat (not that much but the total consumption is only 9W). The heat comes from the base and not the LEDs. I wonder how much power is consumed inverting the household AC to a low-voltage DC. I haven’t been able to detect any heat from LED flashlights, and I’m further wondering if houses of the future will contain low-voltage DC circuits for the LED lighting systems. Cabling could use much lighter gauge wire and thinner insulation – you could even hide it in stick-on tape for surface mounting.
I keep thinking about the AC/DC issue but never enough to start digging up facts. Just naturally lazy I suppose.
Typically one of the ’65W’ replacement LED lamps will emit about 1W of light energy so about 8W is heat compared with the original lamp which will produce 64W of heat!
Radio too. With LED light bulb revolution say goodbye to many distance radio communications from 30-300Mhz. While they thrive on DC it is often achieved through the use of really radio-noisy often insufficiently shielded switching power supplies or forced rectification. And sometimes brief high current pulses to ‘cheat’ higher light output without causing overheating.
Our city has LED traffic lights and even moderately strong FM stations disappear completely at intersections. I have no doubt that this interference affects radios of emergency services too, A whole lotta FCC Title 47, Part 15 violations are going on. Here are noisy radio spectra from cheapies and a street light interfering with amateur radio. It’s not limited to ‘cheap’ products.
Mario Motta made this nice presentation about “Human and environmental effects of poorly designed night lighting”. http://artificiallightatnight.weebly.com/uploads/3/7/0/5/37053463/motta-mario.pdf
More generally, the Belgian Superior Health Council gave these concrete recommendations about the use of LED lamps at home :
To the attention of the industry
1.Manufacturers should limit the fraction of blue LED light as much as possible, especially in screens, night lamps, bedroom lighting.
To the attention of the government
2.Only LED lights of risk category 0 and 1 (see European Norm EN 62471), should be available to the general public on the market.
3.Children under 8 years must be discouraged to use toys with LED screens, at least at the end of the day.
4.Each LED lamp should have been labeled with information on the recommended use, risk and any contraindications (eg. desk lamp, bedside lamp or nursery).
5.The general public should be given information on:
– risk of using LED lighting: direct lighting or close LED lamps, especially with prolonged use for children younger than 8 years, people operated on cataract or without lens and persons suffering from macular degeneration, photodermatoses or using photosensitive medication or cosmetics (certain medicines, creams or ointments);
– risk of using devices with a LED screen: use by children (under 8 years), prolonged or close use during the evening or at night.
6.Due to the lack of data, further investigation is needed:
– the risks of LED lighting for the eyes and the skin in relation to the type of lighting, exposure pattern and characteristics of the person (healthy or with a condition that poses a risk);
– fluctuations (stroboscopic effect) of the light intensity of the LEDs and their possible impact on health;
– aging effects of the spectrum determining phosphors in LEDs.”
Source (report written in Dutch): http://www.health.belgium.be/sites/default/files/uploads/fields/fpshealth_theme_file/hgr_9341_advies_led_a4.pdf
It is very strange that, without any justification regarding health and environment, the reddish glow of incandescents and the orange glow of sodium lamps is now replaced by the blue light of LEDs. Never before, manufacturers were so dangerous to our health and greedy for gain as nowadays!
Modern “white” LEDs are ultraviolet LED with a fluorescent phosphor coating. The colour of the light is controlled by the mix of phosphors.
Unfortunately, all the cheap LEDs from China are blue-white, I presume because the phosphors are cheaper.
LED can exactly match LP sodium, by using the older-style monochromatic orange or Yellow LEDS.
The usual white LEDs don’t have a UV-emitting chip but a blue-emitting one. The phosphor is designed and applied to not absorb all of the blue light. The remaining blue light mixes with the red-to-green band emitted by usual LED phosphors to result in white light.
And that excessive 440 nm blue causes insomnia….
I have worked with LED’s for years. Shortly after the introduction of white LED’s, doctors began warning of the dangers. There is much more at stake than glare. The particular wavelength of blue that is dominant in white LED’s is as harmful to your eyes as ultraviolet light. While a white LED may appear to your eye to have the same color temperature as a fluorescent lamp, the actual spectrum has a huge spike in the blue with LED’s. Some low cost LED’s bother my sensitive eyes almost immediately and I cannot use them. The kind in cheap flashlights for example. But I seem to do ok with name brand soft white lights from major manufacturers.
Hopefully the fad of using blue LED’s as indicators in electronic devices and decorative lighting will pass, because even these low power sources are not completely safe for your eyes.
There is still a lot of controversy over the mechanisms that are involved in saturation of night vision and the recovery times involved:
http://stlplaces.com/night_vision_red_myth/
Another consideration is surgical correction of cataracts using silicone lenses, which do not block UV as does a natural (carbon-based) lens. The eye is sensitive to UV (although not in terms of imaging), and too much can cause ‘sunburn’ of the retina and loss of visual sensitivity. Chromophores in the epithelial cells of the retina, which are not wired in to the optical nerves, absorb UV and perform chemosynthesis to produce melatonin, which affects the circadian rhythyms. https://www.amazon.com/Health-Light-extraordinary-Affects-emotional/dp/0898040981
So-called ‘amber vision’ lenses will block the UV and some of the blue light, while letting all of the red. orange, yellow, and green light in – enough for good visual acuity. Wearing these under the LED streetlights will allow quicker accommodation to darkness and recovery of night vision after they are removed.
Submarine commanders used to wear red goggles before going above deck at night to preserve night vision.
I find yellow light less pleasant to see and to see by than “pure white” or more blue light. Maybe I’m an alien.
I will say one thing about newer cars – the headlights are often *very* misfocused. For a while there, BMW had headlights had a hard cutoff with their projectors to minimize glare for oncoming drivers (with low beams), but that seems to have gone away.
If the future is yellow, I’m going to be a very unhappy camper.
There is something fishy about this press release…the language in it is not standard English, sentence structure is odd. It is however actually on the real official American Medical Association website.
Best example?:
“The guidance adopted today by grassroots physicians who comprise the AMA’s policy-making body…”
The AMA’s policy-making body is composed of grassroots physicians???? What the heck are grassroots physicians when they’re at home?
More?:
“…to minimize and control blue-rich environmental lighting by using the lowest emission of blue light possible…”
“…operate at a wavelength that most adversely suppresses melatonin during night….”
“…blue-rich LED lighting can decrease visual acuity and safety, resulting in concerns [???] and creating a road hazard….”
I thought the article would turn our to be a spoof by third world hackers….but they are apparently serious, about the LED light anyway — but not about editing to make their releases professional.
Looks like normal English to me, and I have no problem understanding it.
Put a warm color filter over the lights (such as rose/orange colored).