I’ve always wondered how light can burn your eyes.
My cousin worked as a welder for a few years. He got zapped several times. Usually a guy working close to him would ask a question about something. He’d raise his shield and get his eyes burned by another welder working elsewhere in the shop. I remember him saying his eyes bothered him for days. Like sunburning your eyes. But it happened in just seconds.
I’m not sure if there is a safe distance. Even 20 ft away its bad for someone to look at a welding arc.
Why is it ok to look at video of someone welding? How does the camera filter out the dangerous light?
Forgive me if I don’t use all the proper technical terms. But a camera can’t capture the amount of energy that is being transmitted by an arc-welder or the sun. It just shows it as the brightest white that can be displayed by your monitor. Which isn’t bright enough to cause pain and discomfort for obvious reasons. If you were looking at the welder or the sun directly, there would be a lot more photons hitting your eyeballs.
“Harmless”? What do you think a laser is made of! Or radiation? (technically light is a form of radiation in the visible part of the spectrum, but you get the idea)
(link also has details of said damage occurring from visible light exposure, like rhesus monkeys having severe damage after 15 minutes exposure to an ophthalmoscope; humans are fortunately more resistant to intense light but not immune)
Imagine a sound that is so loud that it could cause hearing loss. Standing near a Saturn V rocket launch or something.
Now imagine that someone recorded that sound, and played it back for you on a little handheld tape recorder.
Would listening to the recording cause hearing loss? If not, how did the tape recorder filter out the dangerous sound waves?
Watching a video of someone welding means you are watching light produced by your TV. Unless your TV is so powerful that the light can damage your eyes, you’ll be fine. You can stare at an image of the sun on television with a lot less discomfort than starting at the sun in your front yard, right?
Beyond retinal damage, the UV causes a burn to the cornea. This feels like having sand in your eyes, and can last from hours to days depending on how hard you got flashed.
never had a sunburn? sunlight is full of UV which causes sunburns, electric arcs throw off tons of radiation (intense UV as part of it.) Arc lamps like mercury-vapor (the classical street light) throws of a load of UV; the outer bulb envelope filters most of it out. Hell, even halogen incandescents have UV filters.
Keep in mind that the difference between heat that keeps you warm & comfy and heat that reduces you to a pile of ash is just intensity. Too much of anything is dangerous, including things that we normally regard as harmless.
I always thought that it took longer than a few seconds of looking at welding for it to hurt your eyes. I know that I’ve watched for short periods of time without any ill effects.
I misspoke earlier when I said light was harmless. I was thinking of normal light in a house or even outside. I didn’t think about direct summer sun and sunburns. That certainly can hurt someone if they stay out too long.
Thanks again for clearing this up. Avoid looking at Arc Welding and wear Goggles if you’re out in bright sunny snow.
A related question that I asked once but don’t remember getting a solid answer:
Why is it that we can look to the side of a welding arc or the sun and we are OK?
When I am driving facing a low sun in the west, sometimes I have the burning orb of the sun just a few degrees away from the center of the road, so if I am looking straight ahead, I’m almost looking at the sun. For many minutes.
Why doesn’t that cause damage? Isn’t there still a tiny very bright sun-shaped image on my retina, just not in the center?