# How does light from Welding burn your eyes? **URL:** \ **Category:** Factual Questions\ **Created:** [April 18, 2013, 1:34am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991 "2013-04-18T01:34:13Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [April 18, 2013, 1:34am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/1 "2013-04-18T01:34:13Z")
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? My eyes twitch just looking at this picture. [http://stafford.rutlandcitypublicschools.org/files/2013/01/Welding-2013.jpg](http://stafford.rutlandcitypublicschools.org/files/2013/01/Welding-2013.jpg) ---
**Author:** ![Bullitt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bullitt/32/5725_2.png) [@Bullitt](https://boards.straightdope.com/u/Bullitt)\ **Post date:** [April 18, 2013, 1:46am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/2 "2013-04-18T01:46:17Z")
Why is looking at the sun harmful to your eyes? ---
**Author:** ![USCDiver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/uscdiver/32/354_2.png) [@USCDiver](https://boards.straightdope.com/u/USCDiver)\ **Post date:** [April 18, 2013, 1:47am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/3 "2013-04-18T01:47:06Z")
[Photokeratitis](http://en.wikipedia.org/wiki/Photokeratitis). UV radiation is not transmitted through a television. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [April 18, 2013, 1:51am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/4 "2013-04-18T01:51:01Z")
> [@aceplace57](#): > > 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. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [April 18, 2013, 2:05am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/5 "2013-04-18T02:05:14Z")
Thanks. That wiki article was interesting. It seems strange something harmless like light can burn your eyes. UV light is a special case and it can really hurt. ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [April 18, 2013, 2:08am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/6 "2013-04-18T02:08:36Z")
I’ve heard that doctors can actually see the image of an eclipse burned into people’s retinas if they have looked at it unprotected. ---
**Author:** ![USCDiver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/uscdiver/32/354_2.png) [@USCDiver](https://boards.straightdope.com/u/USCDiver)\ **Post date:** [April 18, 2013, 2:09am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/7 "2013-04-18T02:09:14Z")
> [@aceplace57](#): > > Thanks. That wiki article was interesting. > > It seems strange something harmless like light can burn your eyes. UV light is a special case and it can really hurt. Well, keep in mind there is a lot of electromagnetic radiation that isn’t in the visible spectrum. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [April 18, 2013, 2:35am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/8 "2013-04-18T02:35:05Z")
> [@aceplace57](#): > > Thanks. That wiki article was interesting. > > It seems strange something harmless like light can burn your eyes. UV light is a special case and it can really hurt. “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) ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [April 18, 2013, 2:47am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/9 "2013-04-18T02:47:41Z")
> [@USCDiver](#): > > Well, keep in mind there is a lot of electromagnetic radiation that isn’t in the visible spectrum. Even visible light alone is enough to cause damage, as [this dramatic demonstration](http://www.youtube.com/watch?v=8tt7RG3UR4c) shows. In fact, [no UV actually reaches the retina](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3144654/)\*, so all retinal damage is from visible and infrared light. > [@](#): > > \*The cornea absorbs almost all ultraviolet radiation below 295 nm. This includes all UVC and most UVB light. The natural crystalline lens absorbs most light near UVB (300–315 nm) and all UVA light… > > …The remaining propagated radiation spectra ranging between 400 and 1400 nm in wavelength is referred to as the retinal hazard region. (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) ---
**Author:** ![SpeedwayRyan](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@SpeedwayRyan](https://boards.straightdope.com/u/SpeedwayRyan)\ **Post date:** [April 18, 2013, 1:35pm UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/10 "2013-04-18T13:35:04Z")
> [@aceplace57](#): > > Why is it ok to look at video of someone welding? How does the camera filter out the dangerous light? 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? ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [April 18, 2013, 7:49pm UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/11 "2013-04-18T19:49:23Z")
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. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [April 18, 2013, 8:04pm UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/12 "2013-04-18T20:04:59Z")
> [@aceplace57](#): > > Thanks. That wiki article was interesting. > > It seems strange something harmless like light can burn your eyes. UV light is a special case and it can really hurt. 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. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [April 18, 2013, 11:05pm UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/13 "2013-04-18T23:05:53Z")
> [@aceplace57](#): > > It seems strange something harmless like light can burn your eyes. 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. ---
**Author:** ![Nars\_Glinley](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nars_glinley/32/8177_2.png) [@Nars\_Glinley](https://boards.straightdope.com/u/Nars_Glinley)\ **Post date:** [April 19, 2013, 1:35am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/14 "2013-04-19T01:35:33Z")
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. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [April 19, 2013, 2:45am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/15 "2013-04-19T02:45:49Z")
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. ---
**Author:** ![thicksantorum](https://avatars.discourse-cdn.com/v4/letter/t/65b543/32.png) [@thicksantorum](https://boards.straightdope.com/u/thicksantorum)\ **Post date:** [April 19, 2013, 4:22am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/16 "2013-04-19T04:22:42Z")
May as well ask why viewing Chernobyl documentaries doesn’t cause radiation poisoning. It’s the exact same thing. ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [April 19, 2013, 8:16am UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/17 "2013-04-19T08:16:46Z")
> [@thicksantorum](#): > > May as well ask why viewing Chernobyl documentaries doesn’t cause radiation poisoning. It’s the exact same thing. … and \*\*thicksantorum \*\*wins the thread. ---
**Author:** ![SpeedwayRyan](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@SpeedwayRyan](https://boards.straightdope.com/u/SpeedwayRyan)\ **Post date:** [April 19, 2013, 1:57pm UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/18 "2013-04-19T13:57:08Z")
> [@aceplace57](#): > > 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. Yeah, we know. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [April 19, 2013, 4:07pm UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/19 "2013-04-19T16:07:35Z")
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? ---
**Author:** ![Nars\_Glinley](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nars_glinley/32/8177_2.png) [@Nars\_Glinley](https://boards.straightdope.com/u/Nars_Glinley)\ **Post date:** [April 19, 2013, 7:03pm UTC](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991/20 "2013-04-19T19:03:28Z")
> [@minor7flat5](#): > > 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? [This](http://blogs.howstuffworks.com/2009/04/09/why-doesnt-it-hurt-to-look-at-the-sun-during-a-sunrisesunset/) explanation from the founder of “HowStuffWorks” makes sense. [Next page](https://boards.straightdope.com/t/how-does-light-from-welding-burn-your-eyes/655991.md?page=2)