Is it dangerous to look into bright lights?

I've heard this at times here on the forums. Is it true that looking into really bright lights is bad for you? How bad? How bright would a light need to be before it is dangerous? Am I safe looking into my A2 and G2, or is that stupid? I never thought this would be harmful until I came here.

SCblur said:

I've heard this at times here on the forums. Is it true that looking into really bright lights is bad for you? How bad? How bright would a light need to be before it is dangerous? Am I safe looking into my A2 and G2, or is that stupid? I never thought this would be harmful until I came here.

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With all due respect............... what do you think the answer is? Isn't the answer similar to "is it dangerous to walk in the street with moving traffic"? No disrespect intended, but come on.

First of all I must admit that I am no expert, but I don't think that looking into bright lights on a regular basis would be all that good for your eyes. Just like staring at the sun - if you do it for long enough something will give. But seriously I think that it would be best practice to avoid it (looking at the sun and into bright lights).

I agree with TIN on this one. But if you just got your A2 or something and you wonder how bright it is, I dont think it is oging to hurt you just that once. But if you do it everyday, I would imagine after a while it would casue damage.

From my own research what you have to be especially careful of is light in the blue or violet end of the spectrum (the shorter wavelengths) which, above a certain power, can cause photochemical issues in the retina. It is also possible to actually burn the retina or other parts of the eye from a very concentrated beam (such as viewing the sun through a telescope or a strong SLR camera lens).

There are several flashlights that are capable of that sort of output when placed close to the eye and looked at directly.

Apparently this damage is almost never irreversable but are you willing to risk your vision on "almost"? Also, bright lights cause a pain response. This is your body protecting itself and you should listen.

Well I have heard that looking into LED's is worse for your eyes and looking into Incandecent lights, but I'm not sure.
I myself have looked into all of my lights, not from 6" from my face, but I have someone shine them at me at around 30 feet, so I know how they would appear if I were to shine them at another person at a distance that is possibly approaching me. The light isn't physically painful, but it defintely doesn't feel pleanant either.

zespectre said:

From my own research what you have to be especially careful of is light in the blue or violet end of the spectrum (the shorter wavelengths) which, above a certain power, can cause photochemical issues in the retina. It is also possible to actually burn the retina or other parts of the eye from a very concentrated beam (such as viewing the sun through a telescope or a strong SLR camera lens).

There are several flashlights that are capable of that sort of output when placed close to the eye and looked at directly.

Apparently this damage is almost never irreversable but are you willing to risk your vision on "almost"? Also, bright lights cause a pain response. This is your body protecting itself and you should listen.

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Any intense light source is dangerous, but I have also read the blue light is 100 times more dangerous than red. That's not an invitation to stare into bright red lights . I agree that anything that induces wincing, squinting and eye pain can't be good for you. Note that because white LEDs contain more blue than most other colors, they might bad for long periods of time. I do notice more eye fatigue when reading with bluer 5mm light as compared with the warmer tint of an underdriven luxeon.

I looked into the beam of a Surefire Beast at the Ghost Mountain trip. Not sure why I did that. I survived it but I do not recomend it.

I've done this from a distance. Your iris are made to contract with such painful light, but it's not 100%. Occasional blasts will not hurt you, but dont do it at all if you can help it.

Best way is to look at the reflected beam off the wall. Or, put on good sunglasses and quick glance from a distance.

Okay, let me clear this up in my defense. I'm not that dumb. Mind you, before I cam here, the brightest light I knew of was a mag. And no, I don't look into my lights for fun. And yes, it makes sense to me that tactical, bright lights would not be good for you. I'm just wondering how bad they would be. At what brightness level do they begin to be damaging? Don't worry, I am playing with a full deck.

2900 lumens were enough for me. I really don't know what I was thinking...I tried to deny doing it but there were too many witnesses. Don't do this.

Alright then. This is my job (MD, ophthalmologist). You can permanently burn your retina with any bright light source, but it takes a lot of light and it usually takes some prolonged exposure. For example, stare at the sun on a bright day for about ten minutes straight and you'll almost for sure do some damage. A few seconds exposure to any flashlight that's not a laser is unlikely to do permanent damage, but there are plenty of flashlights out there that would do it with a prolonged exposure.

Just use common sense. If it hurts, don't do it. :ironic:

Short wavelength can be more damaging, yes. If you expose yourself to bright UV light like an arc welder for more than a few seconds you're going to get a surface burn, basically sunburn, on your corneal surface. Usually this heals up just fine after a few days.

However, long wavelength light can do damage as well. Glass blowers used to get weird cataracts in the old days from the infrared (heat) radiation from their work...

SCblur said:

Okay, let me clear this up in my defense. I'm not that dumb. Mind you, before I cam here, the brightest light I knew of was a mag. And no, I don't look into my lights for fun. And yes, it makes sense to me that tactical, bright lights would not be good for you. I'm just wondering how bad they would be. At what brightness level do they begin to be damaging? Don't worry, I am playing with a full deck.

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I understand that and like I said, no disrespect was intended. My take is that if causes your pupil to dilate, it must produce some level of harm. Now, saying all that, I can't stand here and say I've never intentionally blasted myself with a bright light.

If the body is sending the signal "discomfort" when you look into a bright light, better listen to your body, you only have ONE set of eyes.
Short wavelengths (blue, violet) cause more harm than longer ones. UV is probably the scariest: You can't see it, your pupils stay wide open, letting all the light into your eyes.
Did I flash myself into the eyes? Heck, yes! But I don't stare into bright lights too long. I still want to play with flashlights when I'm an old man.

SCblur said:

Okay, let me clear this up in my defense. I'm not that dumb. Mind you, before I cam here, the brightest light I knew of was a mag. And no, I don't look into my lights for fun. And yes, it makes sense to me that tactical, bright lights would not be good for you. I'm just wondering how bad they would be. At what brightness level do they begin to be damaging? Don't worry, I am playing with a full deck.

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You're right, SCblur, your question wasn't stupid, and the answer isn't obvious.

For those who missed the point of his question, SCblur wants to know, "At what point does 'causes discomfort' cross the threashold into 'causes permanent damage'?"

As several CPFers have pointed out, damage and discomfort are, in part, frequency-dependent. I think that a second factor is "lumens per unit of arc" of our cone of vision. Let's face it: 1,000 lumens coming from a photographer's light umbrella would probably be tolerable. 1,000 lumens from a tactical flashlight could well cause permanent damage.

I think it depends a little on the frequency components (color) of the light, and then on how coherent is the lightwave of the source of the light.

If the light source is coherent, as in laser beam, you will be in a much bigger trouble because the light energy can be fucused into a much smaller spot on your optic nerves.

Say, you are not a moth, are you?

JonSidneyB said:

I looked into the beam of a Surefire Beast at the Ghost Mountain trip. Not sure why I did that. I survived it but I do not recomend it.

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Nutwing award!

It is especially dangerous if you look into the beam of your Surefire M6 while driving at night on a busy two way highway...I only look into bright lights for a few seconds when I really feel the need to sneeze, yes sneeze, lol. I have very light sensitive eyes, I think I can see in the dark better than most people but in sunlight I have to wear sunglasses almost constantly to see, and not to sneeze constantly. Something in bright light makes me sneeze like crazy. I will probalby sneeze half a dozen times walking out of the house to my truck before putting on my sunglasses on a sunny day, and it is worst in winter.

That is called the photic sneeze reflex...

Well, it certainly can't HELP anything...

Last bright light I looked into was a direct driven T3JG green Lux III. I saw a dark spot for the next two hours.

I repeat, that is the LAST BRIGHT LIGHT I looked into...