Are LEDs safe to look at?

R

rob norton

Veteran
The BBS Area 48 panel does not work unless its remote phosphor panel is in place. Supposedly the blue light it produces can be harmful to the eyes.

I appreciate this admission and am sure LED manufacturers do things to "tick the boxes" but is there any official standard to make sure products aren't causing damage to eyes?

Am I being paranoid?
 
The blue LEDs are near UV, spilling into the UV-A spectrum (315-400 nm) which is harmful to eyes. Standard white LEDs have the phosphor directly on the blue diode material, so minimal UV is emitted.
 
Most lights have UV filtered on them, but this one utilizes that part of the spectrum to function. The Cinemo remote phosphors have a similar design and safety. Most HMIs have a UV filter built into their design as well, sometimes on the lens and sometimes on the bulb itself. Defeating this protection can lead to severe eyeburn (sunburn for the eyes) and even blindness.
 
Mitch Gross said:
Most lights have UV filtered on them, but this one utilizes that part of the spectrum to function. The Cinemo remote phosphors have a similar design and safety. Most HMIs have a UV filter built into their design as well, sometimes on the lens and sometimes on the bulb itself. Defeating this protection can lead to severe eyeburn (sunburn for the eyes) and even blindness.
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This happened to a reporter friend of mine. The clown he was working with had removed the UV safety glass from the HMI. My friend ended up in the emergency room in the middle of the night and it took him a while to recover and be able to tolerate bright lights again. Kind of a set-back when a large portion of your on-air presence is doing outdoor, daytime LS's.
 
Years ago I was testing a inexpensive open-face HID light that's popular with some members of these forums, & thought there might be a UV issue. Since the build quality was consumer at best I pointed it at the ceiling, & left it burning for a few hours. After some time my eyes began to feel like they were burning so I returned it.

Since my test was not comprehensive I'll reframe from naming & shamming the manufacturer.
 
Discharge lights are arcs - so removing the safety glass is stupid and dangerous. LEDs on the other hand have the scaremongers worried, but the UV component that is getting people worried is nowhere near the part of the spectrum where the light is dangerous, and the intensity is quite low compared to an arc.

I personally am not convinced at all by the blue light is bad brigade. There is plenty of about it on the net, but all the sources use words such as "may", "could", "probably", "possibly" and other non-specific descriptors. Looking at the proper medical advice available - the issues come from the practical aspects. Blue light is difficult for our eyes to focus on, it tends to glare and appear to be not quite sharp. It also triggers melatonin production, so sleep can be a problem in areas lit by blue LED sreetlighting.

My own view is that our typical usage is minimal - and my background in theatre lighting where blue light has always been desirable is that I've never found anyone with any poor response to it - now we have blue LED that is bright for the first time ever - blue gel previously used had a light transmission of less than 5% for the darker colours - we see stages washed in bright deep blue with no impact that I have been made aware of.

The interlock on these lights does prevent the 'blam' effect when they suddenly turn on and hit you straight in the eyes close in, but apart from making you squint and having floaters in your vision for a while, I personally do not believe the hype and the info on the web sites. The medical advice is very gentle and generic, but is not really appropriate for us - just I think, the manufacturers being careful and responsible.

I work with bright blue LED frequently and have never had any issues - doesn't prove they are safe, but they won't burn you, wont cover you in red hot glass fragments, and don't hurt your back from their weight so much.

I'm still a sceptic.
 
I have seen the 'lenses' fall off led's due to excessive heat, turning their color temp to a uv magenta, but these were custom built candelabra units and not commercially produced fixtures.
 
paulears said:
Discharge lights are arcs - so removing the safety glass is stupid and dangerous. LEDs on the other hand have the scaremongers worried, but the UV component that is getting people worried is nowhere near the part of the spectrum where the light is dangerous, and the intensity is quite low compared to an arc.

I personally am not convinced at all by the blue light is bad brigade. There is plenty of about it on the net, but all the sources use words such as "may", "could", "probably", "possibly" and other non-specific descriptors. Looking at the proper medical advice available - the issues come from the practical aspects. Blue light is difficult for our eyes to focus on, it tends to glare and appear to be not quite sharp. It also triggers melatonin production, so sleep can be a problem in areas lit by blue LED sreetlighting.

My own view is that our typical usage is minimal - and my background in theatre lighting where blue light has always been desirable is that I've never found anyone with any poor response to it - now we have blue LED that is bright for the first time ever - blue gel previously used had a light transmission of less than 5% for the darker colours - we see stages washed in bright deep blue with no impact that I have been made aware of.

The interlock on these lights does prevent the 'blam' effect when they suddenly turn on and hit you straight in the eyes close in, but apart from making you squint and having floaters in your vision for a while, I personally do not believe the hype and the info on the web sites. The medical advice is very gentle and generic, but is not really appropriate for us - just I think, the manufacturers being careful and responsible.

I work with bright blue LED frequently and have never had any issues - doesn't prove they are safe, but they won't burn you, wont cover you in red hot glass fragments, and don't hurt your back from their weight so much.

I'm still a sceptic.
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You misunderstand the issue at hand. UV emitting lights such as HMIs can cause eyeburn, which is a very real thing. The issue with LEDs is twofold. One is that they can emit UV and also cause eyeburn. While not as severe a hazard as on a emitter such as an HMI, it is a danger. The other is narrow frequency retinal damage. The eye is not designed for narrow band emitters. Over millions of years of evolution, the eye is designed to react to black body emitters, like our sun. A black body emitter is pretty easy to react to, because if certain wavelengths get bright enough to cause damage then a whole bunch will, and the light is so bright we naturally shield our eyes. But a narrow band emitter is quite different. An LED or a laser can emit light on only a small frequency range. Even if that emtter is quite bright, the eye & brain interpret it as not so bright because it is such a narrow band. The effect is that a narrow frequency but extremely bright source can quickly cause damage to the human eye.

Think of a little laser pointer. Every one of them has a warning label noting that they can cause eye damage, but a lazer pointer doesn't look particularly harmfully bright. But it is super bright in its very arrow color frequency, and shining it into your eye for even a second or two can cause permanent damage.
 
Mitch Gross said:
You misunderstand the issue at hand. UV emitting lights such as HMIs can cause eyeburn, which is a very real thing. The issue with LEDs is twofold. One is that they can emit UV and also cause eyeburn. While not as severe a hazard as on a emitter such as an HMI, it is a danger. The other is narrow frequency retinal damage. The eye is not designed for narrow band emitters. Over millions of years of evolution, the eye is designed to react to black body emitters, like our sun. A black body emitter is pretty easy to react to, because if certain wavelengths get bright enough to cause damage then a whole bunch will, and the light is so bright we naturally shield our eyes. But a narrow band emitter is quite different. An LED or a laser can emit light on only a small frequency range. Even if that emtter is quite bright, the eye & brain interpret it as not so bright because it is such a narrow band. The effect is that a narrow frequency but extremely bright source can quickly cause damage to the human eye.

Think of a little laser pointer. Every one of them has a warning label noting that they can cause eye damage, but a lazer pointer doesn't look particularly harmfully bright. But it is super bright in its very arrow color frequency, and shining it into your eye for even a second or two can cause permanent damage.
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Mitch has very nicely explained it. Several years ago a manufacturer in India had told me the exact same thing about LED lights. He was lamenting the lack of standards in LED lighting and was saying how some manufacturers are selling cheap by compromising on the lighting. If the light is not full spectrum, then it will damage the eye. Apparently the LED lighting standards for households are better in EU than in India. Many LED manufacturers dump cheap LED lights. So if we unknowingly expose ourselves to such lightings, then it is not good for our eyes.
 
There is a general concern that LED's are harmful to vision in the longterm as a result of the intensity of LED lights. What is known as "LED Phytotoxicity".

https://www.ncbi.nlm.nih.gov/labs/articles/27751961/

There is a convenience store near where I live and the store installed a strip of blue LED lights on the exterior of the building that are so intense as to cause you to squint. The LED lights on police cars can be blinding at night. Enough to cause a wreck. And then there are the LED signs and billboards that are extremely intense in their output.

In total it is a form of "light pollution" and LED's, as a result of their intensity, are especially culprits.

Whether harmful to the human eye or not, LED's often make for an ugly world. A garish, oversaturated, gaudy world. Even neon lighting was less offensive than much of today's use of LED lighting. LED lighting's comparative low power consumption and high output ability facilitates offensive use and irresponsible use. It's like the AK47 of lighting technology.

https://www.newscientist.com/article/dn26383-lighting-cities-with-cheap-glaring-leds-is-a-dim-move/


"studies have shown negative environmental and health impacts from blue-rich white light sources. They increase glare, creating potential safety problems for motorists and pedestrians, and excessive artificial lighting disrupts the behavior patterns and reproduction of nocturnal animals.

Solving LED light pollution isn’t so much a technical issue as a social one. People have a tendency to use more of something, not less, when it becomes cheaper to produce. Although LED is a more energy-efficient technology, lowering the cost of producing light is not expected to reduce light use or even maintain current use levels."

https://spie.org/membership/spie-professional-magazine/spie-professional-archives-and-special-content/2016_january_archive/led-light-pollution

"artificial light is the most drastic change humans have ever made to Earth's environment."


http://www.nola.com/outdoors/index.ssf/2016/06/light_pollution_from_leds_is_w.html
 
I'm very dubious of many of these claims as the physics they use is subjective and lacking context. The studies seem centred on contrast ratio, not brightness. The actual brightness of LEDs is very low compared to the existing so called 'dangerous' light sources, like arcs, the sun, focused incandescent lighting. The examples above of blue police lights are very true - but we are talking about very low night time ambient light levels, where the iris in the eye is relaxed and wide. The centre of our field of view is also not that sensitive to colour, so what happens is that the eye effectively has it's gain turned up, and then the bright source of light - as in the blue police lights are received by the parts of our eyes not dead centre, so the auto iris we all have doesn't shut down very accurately, over saturating our corneas with blue light. Circadian rhythms and the other impacts on our health are no doubt influenced by lots of blue light that evolution links to the length of day and night.

This all comes apart in the day time, when the relative LED brightness of the police car is much lower because our irises are more narrow, restriction g light ingress.

We're seeing physical results because they are there, but any form of odd lighting causes this. LEDs are getting better all the time, but we're blaming them for being good - not being dangerous.

This is all green spin. I choose to ignore it - at least until some logic is inserted that provides real evidence. Any light source washing a town with blue light will cause the same issues - but it's the scale that gets me. Blue light is being made a danger, when it really is not.
 
paulears said:
.... The actual brightness of LEDs is very low compared to the existing so called 'dangerous' light sources, like ... the sun, .....
Click to expand...

Excellent point. We are flooded by intense blue light every day by the sun for a lifetime. No one is concerned about the blue coming from the sun. We know the UV dangers of the sun and are not concerned about the blue spectrum. LEDs do not put out UV. The spectrum radiated by LEDs is easily controlled. I'm retracting my earlier post as nonsense.
 
We squint or wear sunglasses when looking at the sun. But if we remove all of the wavelengths of light emitted by the sun with the exception of a narrow band of blue, then that wouldn't appear very bright but could have just as much dangerous radiation as the full sun.
 
Does any of these concerns pertain to the cheapo LED lights frequently used for video (sub-$100 Amazon/ebay)?
Is there potentially safeguards missing in them?
 
GHKAM said:
Does any of these concerns pertain to the cheapo LED lights frequently used for video (sub-$100 Amazon/ebay)?
Is there potentially safeguards missing in them?
Click to expand...

Highly unlikely, but I guess anything is possible.

If you look at the extreme frequency sapphire blue LEDs utilized by Remote Phosphor lights from Cineo and BBS you will see that there is a huge difference between them and the blue LEDs in a standard RGB LED array. It is this extreme form of LED that poses the danger. But as someone else noted, there are some cheap HID fixtures available on the market that do not provide any UV protection in the fixture design. These lights can accept bulbs with the UV protection incorporated into the coatings on the bulb enclosure, but one can also buy bulbs without UV coating, which is where the danger arises.
 
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