LED = Eye Damage?

[elgarak]

In Europe you have laser class directives regarding LEDs, which you do not have in the US (strange but true).

According to these directives all LED lamps which are laser class 2 or higher has to have a warning sticker on the lamps. But if you have an LED with laser class 1 you do not need to have this sticker due to that the LED is safe.

If you look at the LED datasheets most of the LED suppliers have the laser class information printed.

Well, the strange part is that LEDs are included in the European regulations. What happened is that they wanted to outlaw laser pointers to be abused by kids. So they reformulated the laser regulations. But, being politicians and lawyers, and not MDs, scientists and engineers, they came up with a definition that happened to include LEDs as well as laser diodes.

Most professionals I know consider the current regulation ridiculous because of this -- it does not say anything about the danger of the device due to the inclusion of safe/less dangerous devices in the same class as truly dangerous ones.

 

[half-watt]

Well, the strange part is that LEDs are included in the European regulations. What happened is that they wanted to outlaw laser pointers to be abused by kids. So they reformulated the laser regulations. But, being politicians and lawyers, and not MDs, scientists and engineers, they came up with a definition that happened to include LEDs as well as laser diodes.

Most professionals I know consider the current regulation ridiculous because of this -- it does not say anything about the danger of the device due to the inclusion of safe/less dangerous devices in the same class as truly dangerous ones.

many thanks for the clarifying remarks. they sure put the OP info into context.

 

[Pax et Lux]

I'm sorry to muddy the waters further here, but the answer could be as simple as it's HID lights that have the potential to cause eye damage (because, I believe they emit a wider range of radiation) and someone, somewere confused HID and LED or thought they were one and the same.

Of course, I'm not sure about the radiation leaving an HID light, but I seem to remember reading something on Flashlightreviews.com sometime ago about it being unadvisable about looking into the light - which it is, with any flashlight, really. When I get time I'll try to find it.

 

[Luminescent]

The DANGER presented by high brightness IR and UV LED's is very REAL.

When I saw that DX was offering 1W level UV LED emitters, I immediately envisioned some poor jerk wiring one of these things up, and over-driving the crap out of it while staring into it and wondering why it didn't look 'brighter' (only to discover in very short order that NOTHING looks bright anymore because all his central vision is GONE).

DO NOT MESS WITH HIGH BRIGHTNESS IR OR UV SOURCES, UNLESS YOU HAVE PROTECTIVE EYEWEAR AND KNOW EXACTLY WHAT YOU ARE DOING.

As far as what may be driving objection to high brightness WHITE LED's goes, I think there are really TWO different issues:

1. Modern high brightness LED's have an extremely high surface brightness level which should not be viewed directly even briefly. Fortunately, the blink reflex is likely to protect the eye (except for high brightness IR and UV LED's as noted above).

2. Even when viewed indirectly, very bright LED sources may have some ergonomic viewing fatigue issues due to the spectral distribution of the light.

Number 1 above is a very real concern for UV and IR LED's (because pupil contraction and the blink reflex does not work for these sources), but seems a little silly to apply to high brightness white LEDS, because any moron who is so determined to destroy his or her vision, by staring into a bright white LED, can just as easily go outside and stare into the sun to accomplish the same purpose (so banning bright white LED's to protect these idiots from themselves doesn't make any sense).

I think the second issue is pretty minor as well, but to understand the concern, take a look at the Wikipedia entry on LED's and note that the spectrum chart for a 'White' LED actually has a really huge blue spike (caused by leakage of the blue driver through the phosphor layer).

Here are the links to the main article and the full size spectrum plot:

http://en.wikipedia.org/wiki/Light-emitting_diode

http://en.wikipedia.org/wiki/Image:White_LED.png


The statement that white LED's emit ZERO UV is a bit of an oversimplification.

Having tested laser and led components professionally, I can tell you that an LED's output spectrum is quite wide and varible (due to process control issues).

The Blue light leakage spike in a white LED borders on the 400nm region that represents the boundary of the Near-UV to start with, and with the wide spectrum (and process control variations in the manufacturing of LED's), some LED's will almost certainly leak some energy which extends into the near ultra-violet.

As someone has already commented, 'white' LED's are really great at exciting fluorescence in 'day-glow' colors, and this behavior is no doubt a result of leakage of these highly energetic blue-violet spectral components through the phosphor.

Even if the spectrum is on spec, the ultra bright blue light is quite actinic (able to excite photo-chemical effects), and could cause viewing fatigue or even 'snow-blindness' if viewed at high brightness for extended periods.

I personally find the spectrum from white LED lights slightly irritating to use unless I keep the brightness reasonable, and use 'warm' color balance LED's (where more of the optical energy has been shifted into the longer wavelengths).
[FONT=&quot]
Certinly, dispite the strong blue-violet component, LED illumination is not as dangerous as say, unfiltered sunlight for example, so I don't think it makes any sense to go overboard on this second issue, as long as folks show a little common sense.

Despite the above facts, there will no doubt be some self-appointed ergo-nazi twits who will seek to legislate to protect us from the evils of artificial light. Of course, If we listen to these luddites, it would probably be better that we should avoid ALL artificial technologies and live happily as nature intended (short brutal lives, in cold dark caves).[/FONT]

[FONT=&quot]On the other hand, once again (at the risk of repeating myself) UV and IR LED's are a different matter;

PLEASE DO NOT MESS WITH HIGH LEVEL IR OR UV SOURCES, UNLESS YOU HAVE PROTECTIVE EYEWEAR AND KNOW EXACTLY WHAT YOU ARE DOING.[/FONT]

 

[Led_Blind]

Those that promote laws that 'are for your own good' are the bottom feeders of society. They actively attempt to dumb down the issues and fear knowledge (they'd be out of work). Here's an odd warning, I purchased a good quality knife set recently. It contained the warning 'Not intended for human or animal use' .... ummm huh?

I was recently with a 6yr old cousin in a shopping centre eating a doughnut treat. Little Leah after finishing her own went to pinch what was left of my own and received a very quick but playful slap on the hand and proceeded to guilt me through facial expression. It was at that point that some nosey old menopausal bag comes along and gives me an ear full for spanking my child in public. This in turn attracted the attention of the shopping centre security who quickly came to the conclusion that I was a bad father.
My little cousin decided she did not like these people and said to me "that old lady is scary, can we go now?" My response "Yeah, just a sec" I overtly took down the badge numbers and names of the guards with no explanation, turned and left hand in hand with Leah.

Sorry for the rant but the basic issue is the same, think before you act. If you cannot envisage the issues or problems then research and understand. If done you can play with all manner of dangerous toys and be fine. This includes playing with high powered UV or IR sources that can be fun, educational and SAFE. I think Luminescent already said this tho….

Oh and one more titbit, I am (unwillingly) and occupational health and safety officer for our office. This involves attending mandatory training days discussing of all things, adequate signage for dangerous situations. One that came up was the requirement that there be a sign indicating a smooth kitchen floor would become slippery when wet and all spills should be cleaned immediately. Ok fair enough, clean up your spills because it is obvious that a wet floor is more slippery, unhygienic and unsightly. When I commented that slippery when wet was common sense so unneeded i was asked what common sense was my response was "it is the knowledge that tells you not to look down the barrel of a loaded gun to see why it was not firing" The trainer had no comeback.

 

[CdBoy]

Stare into any Light Source for a looong time and tell me if your eyes is still ok or not and i will tell you "you are one crazy guy!" heh heh.

do everything in moderation is the old adage that is.

 

[WadeF]

The DANGER presented by high brightness IR and UV LED's is very REAL.

Could you comment on some of the UV lights shown here?

http://www.lighthound.com/index.asp?PageAction=PRODSEARCH&txtSearch=uv&btnSearch=GO&Page=1

I have the 12 LED one, and the smaller key chain model. Are these dangerous to shine around and look at items light up from these lights without protection? Or are these no worse than being around black lights?

 

[Monocrom]

Or are these no worse than being around black lights?

I've seen lights like that before.... You pretty much hit the nail on the head with your last sentence, Wade.

 

[orionlion82]

(Snip!)

Despite the above facts, there will no doubt be some self-appointed ergo-nazi twits who will seek to legislate to protect us from the evils of artificial light. Of course, If we listen to these luddites, it would probably be better that we should avoid ALL artificial technologies and live happily as nature intended (short brutal lives, in cold dark caves).[/FONT][/FONT][/SIZE][/FONT]

[FONT=&quot]On the other hand, once again (at the risk of repeating myself) UV and IR LED's are a different matter;

PLEASE DO NOT MESS WITH HIGH LEVEL IR OR UV SOURCES, UNLESS YOU HAVE PROTECTIVE EYEWEAR AND KNOW EXACTLY WHAT YOU ARE DOING.[/FONT]

From Rainer Maria's "better version of me" - Artificial Light.

no one defies artificial light.
simultaneous sitting 'til you atrophy
maybe you try to be pretty instead of kind
why is this technology an anathema to me?
if i could just breath it out....
i could always breathe back in
i'll cut all your wires
i never cared
cut all your wires
what can be there? it's dead.
and all the invisible arcs
are caught in my head
and the invisible arcs
are caught in my head

it works out as a good MSDS for instructional purposes here.

i just happened to be listening to it while i read the thread ironically enough...

note the reccomendation to allways breathe back in as well!
its a saftey song!
and the more you read in to it the more it applies in this context to this thread. fascinating when you study it carefully and think about what we are talking about here...

 

[brightnorm]

Craig (LED MUSEUM) answers the question of UV radiation in the spectral charts included in many of his reviews. I looked through about a dozen and found that with remarkable consistancy all of the lights produced very little UV.

Here's an example (Fenix P3D-CE)

http://ledmuseum.candlepower.us/ninth/p3d1.gif

I can't say this is representative of all LED lights, but it certainly appears encouraging for those of us who fear UV overexposure. A question that remains is whether those same curves apply when the lights are run at greater intensities.

Brightnorm

 

[orionlion82]

Craig (LED MUSEUM) answers the question of UV radiation in the spectral charts included in many of his reviews. I looked through about a dozen and found that with remarkable consistancy all of the lights produced very little UV.

Here's an example (Fenix P3D-CE)

http://ledmuseum.candlepower.us/ninth/p3d1.gif

I can't say this is representative of all LED lights, but it certainly appears encouraging for those of us who fear UV overexposure. A question that remains is whether those same curves apply when the lights are run at greater intensities.

Brightnorm

well, overdriving any component/assembly throws the rulebook out the window and you are on your own.

 

[Handlobraesing]

well, overdriving any component/assembly throws the rulebook out the window and you are on your own.

Not in the US civil court.

 

[Quickbeam]

"In Europe you have laser class directives regarding LEDs, which you do not have in the US (strange but true)."

Not strange at all to me. The US isn't (yet) a huge nanny state like most Euorpean countries that feel the need to tell everyone what they can and can't do "for their own good". Although we're trying like heck to get there, aren't we...

White, blue, and green LEDs are not going to cause eye damage if you use common sense and listen to your body. If it's bright and we look at it, we have a natural aversion reaction (we blink and look away). The effect is no worse than momentarily looking at the sun by accident and turning away.

I lump those warnings I see on LED lights in the same class as those found on my wife's hair dryer that say "do not use while sleeping". Stupid and useless. "Do not stare into beam". No kidding... Duh.

You may also find with a little searching that the information that some folks quote about blue and green LEDs being dangerous is actually from research into the danger of blue and green LASERS, not LEDs. The research evidence is frequently expanded by do-gooders to encompass LEDs in addition to LASERS, which is completely incorrect.

 

[half-watt]

The research evidence is frequently expanded by do-gooders to encompass LEDs in addition to LASERS, which is completely incorrect.

You mean to tell me that they're NOT the same thing? They both begin with the letter 'L', don't they?


sincerely yours,
Mr. D. O. Gooder

 

[Luminescent]

Could you comment on some of the UV lights shown here?

http://www.lighthound.com/index.asp?PageAction=PRODSEARCH&txtSearch=uv&btnSearch=GO&Page=1

I have the 12 LED one, and the smaller key chain model. Are these dangerous to shine around and look at items light up from these lights without protection? Or are these no worse than being around black lights?

[FONT=&quot]There are several things working in your favor to make this style of light safer.

First, lights like the one you posted the link to should be designed to only produce long-wave UV, which is much safer than short-wave UV (this is the UV-A / UV-B issue you have probably heard about). On the other hand, some portable lights are produced for mineral prospecting, which requires short-wave UV, so if you see references to a UV light being sutible for that purpose, look out!

[/FONT][FONT=&quot]Second UV LED technology is only slowly catching up with the ultra bright visible light LED devices, so your UV LED's are probably nowhere near the UV equivalent of those 100000mcd white LED's which are so blinding bright in the visible spectrum. This is why you can just barely get something across the room to fluoresce (a single 40 Watt Long Wave UV fluorescent light will have a hole room glowing very brightly by comparison). So, fortunately, the UV level produced by this type of light is fairly moderate.[/FONT] [FONT=&quot]

Third, your light uses multiple 5mm LED's which spreads out the source brightness, which is nowhere near as bad as looking into a single 1W high power device.

So using your light to illuminate items for close-up examination should be perfectly safe, if you keep the duration of exposure reasonable, and use a little common sense.[/FONT][FONT=&quot] For example, I would not look directly back into the light if you can avoid it, as that's the worst-case scenario.[/FONT]

 

[Monocrom]

Anyone still worried about the effects of LEDs, should go back and re-read post #53.

 

[Daviesow]

Regarding statements such as this:

...because any moron who is so determined to destroy his or her vision, by staring into a bright white LED, can just as easily go outside and stare into the sun to accomplish the same purpose (so banning bright white LED's to protect these idiots from themselves doesn't make any sense).

I couldn't agree more with the basic message that those who have been given some common sense should be expected to use it. However, in throwing around terms like "moron" and "idiot" you seem to be forgetting that some people, through no fault of their own, just don't have any common sense.

I have three young children; the youngest is just a few months old. Now I could sit him down on the floor and hold warning labels in front of his face. I could yell "You had better not look straight into this lamp young man!" till I am blue in the face. Somehow I don't think this will have any effect on his natural tendency to stare into bright lights.

The point is, people concerned about the blue light damage are not just worried about specialty lamps and toys. These can obviously be kept away from children. The concern is with the screw-in incandescent replacement bulbs being put into use throughout the home.

So, yeah, if my son were in his 20s and spending a lot of time staring straight in to newfangled light sources I'd go ahead and join you in calling him an idiot and a moron. But for now, give him a break...

Unfortunately, this means "Just don't do it" isn't a very helpful answer to the question of what looking at these sorts of light sources will do to your eyes.

 

[Stress_Test]

From CREE's website, regarding LED and eye safety:

http://www.cree.com/products/pdf/XLamp_EyeSafety.pdf

 

[BigBluefish]

From CREE's website, regarding LED and eye safety:

http://www.cree.com/products/pdf/XLamp_EyeSafety.pdf

Looks like the XP-E is the way to go, if you're concerned about risk from blue light exposure.

I'd say best to keep all (even your low-lumen output) LEDs away from the kids.

 

[Per-Sev]

So I am really confused here do we stare into our lights or don't we, I like to sit down in the evening and turn out all the lights and stick my light in my eye turn it to high and just look at all the pretty colors so now your saying that's bad, next your going to tell me that playing Russian roulette my semi auto Glock is dangerous. Make up your mind please I can't have any fun now.