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LED reef lighting dangerous?!


Salty_Snack

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HecticDialectics

So are you just trolling supernip or do you really think staring at a LED is some special hazard over staring at a MH?

 

the only other point is that 455nm light might cause damage... which is laughable. The blatantly obvious response is that all reef lighting has 400-480nm light. :rolleyes:

Edited by HecticDialectics
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You think a halide puts out similar amounts of blue spectrum as the typical amount of LEDs used by the avg. reefer or any overexposure to high light levels won't cause eye damage, hd?

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devilsadvocate
The very first recorded inhabitants here on Earth was about ~6,000 years ago. That's a loooong time. I'm

i literally just laughed out loud. modern humans came about 60,000 years ago.

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HecticDialectics
You think a halide puts out similar amounts of blue spectrum as the typical amount of LEDs used by the avg. reefer or any overexposure to high light levels won't cause eye damage, hd?

 

Reread my post and get back to me with an accurate question.

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supernip, I don't want to go off on a tangent here, but the american cancer society is exactly one of the groups that hyped UV problems. If they had to turn around and say that moderate amounts of sunlight are healthy for you it would be a major climb down for them. The tipoff is the title of that page - How do I protect myself from UV rays. And if you want to link to things:

 

John Hopkins - Sunlight lowers cancer risk

Sunlight better than a stroke

Vitamin D lowers blood pressure

African Americans and Rickets The amount of time you need in the sunlight is only short for pale people in low latitudes. Darker skin and higher latitudes need more.

Vitamin D and asthma

 

And don't forget that they started adding Vitamin D to milk because people weren't getting enough vitamin d BEFORE the skin cancer scare and everyone started covering up. My point being don't freak out and don't over-react. High amount of sunlight = bad, moderate amount = good, low amount = bad.

 

As to the staring at the lights thing. I don't stare directly at my lights and I bet few people do. Those that do for any period of time probably deserve a darwin award. That point is irrelevant as no one does it. What is relevant is the amount of light exposure from staring at the tank.

 

But go read the linked articles again. What are the warnings:

RG-2 (Moderate Risk): CAUTION. Do not stare at exposed lamp in operation. May be harmful to eyes.

RG-3 (High Risk): WARNING. Do not look at exposed lamp in operation. Eye injury can result.

 

So again, don't look into or stare at the exposed lamp (i.e., the LED) which you admit no one does. So don't panic and freak out from looking at the reflected and diffused light coming from your aquarium. Same way you don't look directly into or stare at the sun, but don't freak out from walking around in the sunlight.

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The very first recorded inhabitants here on Earth was about ~6,000 years ago.

 

I have a picture of Jesus holding a dinosaur as my avatar, and I approve this message. Lol

Edited by solefald
  • Haha 1
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I am around LEDs all day, on and off, i have 20/20 vision, but then again I wear polarized oakleys 24/7.

 

While I do not think LEDs produce anymore harm then traditional reef lighting, it is something I would still like to look into. I would like my customers to be aware of such harms, no matter the seriousness of exposure.

 

Not everyone has common sense and some people would appreciate the warnings, so it is something definitely worth looking into (err, bad choice of words, but you know what I mean, I hope).

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HecticDialectics
you reread mine

 

You linked to a site about UV rays when the question was regarding blue light, lol. Protip: BLUE is not an ULTRAVIOLET wavelength.

 

U reread mine.

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Captain Hook
but then again I wear polarized oakleys 24/7.

 

"I wear my sunglasses at night so I can so I cannnnnn seeeeee" lol couldnt help...cant believe this thread is still going on about D***-all.

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doppelganger

The sun is bad for you, fast food is bad for you, pollution is bad for you, cell phone's are bad for you, computers/tv's are bad for you...

 

Bottom line, if you stare into you leds and it hurts and you keep staring... you're an idiot.

 

I'm more likely to get hit by a bus probably. Doesn't mean I worry about it every day. I've got enough things to worry about giving me cancer, heart disease, and whatever. I'm going to enjoy my tank while I still can.

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Not the most insanely ignorant thread on Nano-Reef, but ranks up there. I'm beginning to rank LED critics up there with creationists in terms of science skills.

 

I strongly encourage you to read "The Blue Light Hazard" part on the following website and judge for yourself.

 

The typically Saturday afternoon infomercial has better science. The amount of blue energy being directed at us from artifical light sources is a fraction what the sun transmits to us in a matter of seconds on a sunny day. So, feel free to sit indoors under your high pressure sodium lamp.

 

I personally noticed that my eyes couldn't focus as well after looking at reef tanks with excessive blue.

 

My eyes don't focus well after doing shots of Jack Daniels, but I don't need a doctor to tell me that. Our eyes don't focus well with blue light either, and it's evolution, not LED's.

 

I don't think anybody disputes the danger UV-A poses to the human eye, but the fact is LEDs, especially white LEDs don't emit photons in this wavelength. There are only a handful of LED fixtures that incorporate 400nm LEDs, and those are at such low power levels they are unlikey to cause retina damage even if you stared at them. Spectral emissions for LED's are widely published and widely known...lots of energy between 440nm-460nm, and the rest depends on the color temp of the phosphor used.

 

Halides however do emit UV-A, but the amount is highly variable depending on the bulb used and the filtering of the jacket. Sanjay Joshi has done extensive testing of reef halide bulbs and his results are posted on the web. Short form is white LED's emit no UV-A, and royal blue LED's emit zero UV-A.

 

Individual LEDs used in reef fixtures are typically 2-3watts each, and even though they have a lot of surface brightness the total amount of energy emitted by each is miniscule compared to a 400watt reef halide which emits most of it's energy in an even narrower band at 450nm from a capsule 1" in size.

 

At present I'm not aware of any tanning beds that use LED's. They all use tubes...basically because LED's are sucky sources of UV energy. A lot of reefers use 420nm actinic tubes, which emit more light closer to UV-A than LED's ever could, but I noted we don't have threads started about the dangers of 420nm light. Why is that?

 

Otherwise, the total amount of blue light we're generating over our tanks with LED is about the same or less as halides or T5's given the greater efficiency of LEDs at generating blue light plus the optics we're using. The average LED fixture is 30-70watts and emits no UV-A, while the halide it replaced is 175-250watt, has unknown amounts of UV-A emission, and if it's an older ballast would kill you if shorted.

 

Last, LED diodes are not laser diodes because they have neither spatial nor temporal coherence. You cannout beam the energy from a 3watt Cree into a 5mm exit pupil from a range of 5feet like you can a laser.

 

So, the only remotely logical arguement some peole have here is attacking reef lighting in general, in which I think I speak for most of us and would ask you to go to a different forum, or do the gene pool a favor and play with a 400watt halide ballast in your bathtub.

Edited by blasterman
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Salty_Snack

WOW, I see this thread has derailed with mostly conjecture and anecdotal evidence. So lets recap...

  • Everything in your tank is dangerous so whats one more thing
  • Humans have been around a really long time
  • I do it and I'm OK so there couldn't possibly be any risk
  • Something about UV light and vitamin D
  • The sun is bright and you shouldn't look at it or your an idiot
  • 455 nm light cannot cause damage HAHA. See blue light hazard page of wicked lasers website: http://www.wickedlasers.com/laser-tech/blu...ght_hazard.html
  • And Jesus holding a dinosaur... still don't understand that one.

 

So thanks for all that, at least some of it was amusing. Just a other things I've found...

 

The sun is bright and can damage your eyes. What is interesting is that at the mid 400 nm range of the spectrum the solar irradiance at sea level is around 0.9 W*m^-2*nm^-1 and the Cree XR-E RB has an irradiance of 0.22 W*m^-2*nm^-1 at 20 cm or ~8 inches. So yes, the sun is much more powerful in that range of frequencies but the LED isn't as far off as I had assumed. (comparison: XP-E RB has an irradiance of 0.077 at 20 cm.)

 

Another interesting thing is our eyes sensitivity to different frequencies of light. We are most sensitive to green and yellow light and least to red and blue/violet. The potential problem this presents is a royal blue or blue LED only emits ~450 nm light and very little else, FWHM is typically about 50 nm. While most MH and CF lights emit light well into the green and red, even with a color temp of 14000K. The point is when you look at or near a bright light that contains parts of the visible spectrum other than blue your immediate response is to blink and look away but for blue light you might think its not that bright when in fact it is, your just not that sensitive to it. Also, blue light scatters much better than the longer wavelength colors.

 

So even if current LEDs are relatively safe it seems that we may be on the cusp of passing that threshold. A real hazard from blue light exposure may occur in future generation LEDs since I can only imagine them getting brighter.

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buckeyes2k7
The very first recorded inhabitants here on Earth was about ~6,000 years ago.

 

I have a good source that says recorded inhabitants were here about 6,001 years ago......Bing.

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yeah it's obvious to me that i shouldn't look at the light. Apparently some of you guys didn't know that looking into the lights is bad. lol really just common sense to me.

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HecticDialectics

I suggest you get on Google Scholar or Pub Med and do some "blue light hazard" research. The only damage occurred when monkeys were forced to stare into blue LEDs for like 40 minutes lol. People who have looked into this in humans, instead of rats and monkeys, haven't found similar occurrences. On PubMed there's an article about sun, plasma arc welding, and various types of light in a epidemiology study on humans... no effects from anything but the most intense light. Hint: reef lighting is not intense in the grand scheme of things.

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This thread is interesting, it's nice to see that my suspicion is correct that they aren't "dangerous" like my parents were nagging me about.

Edited by jm82792
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devilsadvocate

uh, so basically dont stare into your lights for 40 minutes at a time and youll be ok?

i feel like 1/2 the population wont be able to understand this.

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  • 7 years later...

I understand this is an old thread, but many people here don’t understand the point they were trying to make is that the long term effect on staring at the tank under blue spectrum, not the LED itself. Hope they continue this interesting topic as I wanted to find out As well. Peace.

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