When is an LED hazardous to your eyes?
When is an LED hazardous to your eyes?
(OP)
Is there a way to calculate the danger like they do with lasers? I have 18 watts worth of LED's in a reflector. I know it is extremely bright, and looking at it directly for a split second will cause "floating images" in my vision for a few minutes.
So I know it's not good to look at, but "how not good"? Can it cause blindness? I have the specs for the LED's...
So I know it's not good to look at, but "how not good"? Can it cause blindness? I have the specs for the LED's...





RE: When is an LED hazardous to your eyes?
Have no idea if risk can be calculated. But arc welding definitely produces eye problems if you look at the arc for a few seconds. Thought that was due to UV radiation, though.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: When is an LED hazardous to your eyes?
"Art without engineering is dreaming; Engineering without art is calculating."
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RE: When is an LED hazardous to your eyes?
If you think of a light bulb most incandescents of 100W or more are going to have surface brightnesses that exceed sunlit snow.
So looking directly at a light bulb is painful and not advised and probably physiologically controlled via pain/learning.
Now when you get to light sources that are as bright as the Sun's surface you have a different problem. That being that a brief glimpse or a non-center-of-vision view can do harm.
In my university work I worked with lasers constantly. In one case I had to assist with the alignment of a Argon Ion laser at a commercial grating maker. Before I went I did the calculations on the spot brightness. It was about 10 times the surface brightness of the sun. This means that as your eye sweeps across any surface that the beam is striking you risk instant retinal tracking. Even worse because the laser's light was in the visible spectrum your eye will attempt perfect focus of the spot. Furthermore human nature is to look directly at bright colored spots. I took this information to the customer and pointed out that if that beam hit anything in the room even a mat finish and a person looked at it even briefly they were in trouble. No one should even enter the cell without eye protection. We subsequently accidentally drilled a hole thru one of the spacial filters by briefly misaligning the beam path.
So if your light is not meant to be 'looked at', (bright sunlit snow), and is not so bright as to cause instant or near-instant damage,(bright as the Sun's surface), you probably don't have anything to be concerned with.
Just do the math.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: When is an LED hazardous to your eyes?