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I have a slight eye damage in one eye from working with lasers that were just a bit outside the safe limits. And I realized that only years after getting it. S
by cyberax 3y ago
I have a slight eye damage in one eye from working with lasers that were just a bit outside the safe limits. And I realized that only years after getting it.
So the last thing I want, is to be near unconfined lasers powerful enough to ionize the air.
- CodeArtisan 3y agoHow did you realized you had eye damage?
- BikiniPrince 3y agocheck engine light in the upper left hand corner of his vision.
- utensil4778 3y agoTypically you'll notice a persistent black spot in your vision. Particularly if you're looking at a bright field like a blank white page on your monitor.
- jessriedel 3y agoCite? My vague understanding of how vision works is that your brain will tend to interpolate over missing data rather than perceive it as black. So you need to actually test whether you can discriminate things in the affected field of view.
- atomicnumber3 3y agoVision is complicated. Everyone's vision experience is slightly different. So different people might notice different things.
- __MatrixMan__ 3y agoThis is not a citation, but... I have this spot in my right eye that resembles dead pixels. Just tiny blackness. If I let my eyes try to focus on it, it moves with my eyeball, so then they try to focus on the new location... ad infinitum. So they sort of jitter on a path upwards and to the right. I can only see it in certain lighting. Eye doctor couldn't see anything wrong with the area and suggested it might be a floater that got attached and would go away on its own within 6mo. That was 4yr ago and it's still around. It's not getting worse so it doesn't bother me, it just reminds me of the saa from the Wheel of Time. I would have expected interpolation versus vision artifacts as well, but apparently that's an "only sometimes" thing.
- lurquer 3y agoYou have a speck of gunk in your vitreous near the focal point. Not retina. You can’t ‘see’ damage to your retina… you brain just interpolates. The gunk in your vitreous can stay there a long time… it’s gel, more or less, and can take a long time to move.
- philipswood 3y agoMy dad has quite a severe spot where his retina detached in the one eye. Right in the centre of his vision. He reports it looking like a visible hole with surrounding distortion. Apparently similar to some renderings of black holes. That said, this is a large defect in the centre of vision - it's pretty much un-interpolatable. I understand smaller defects not in the macula just get interpolated away.
- thesuitonym 3y agoYou're asking for a citation for someone describing their personal experience?
- jessriedel 3y agoThe comment by utensil4778 I am replying to made a generalization and did not mention their personal experience (although the phrasing maybe suggested that their experience was consistent with the general claim).
- utensil4778 3y agoGenerally, yes. That's why people tend to go for quite a while before noticing the damage. The mechanism isn't perfect and there are plenty of scenarios where your brain doesn't fill in the information, like the one I described. You also see it when looking at repeating patterns. It isn't something super obvious and if you choose to ignore it, it mostly goes away. If your brain magically filled in the missing part of your vision in all cases, ask yourself how we would ever know that anyone has any amount of damage to their vision. Obviously we do know, since people talk about it. There must be some mechanism by which the damage becomes apparent to the patient.
- TrainedMonkey 3y agoDon't know how OP did it, but I've been tested a couple of times at the optometrist by field of view machines*. You concentrate on a central point while the machine shows you a pictogram in a random location with a random timing. You click a button every time you see one. Note: not an actual name, I don't know how these are called.
- cyberax 3y agoIf I look at a straight line with the right eye, I see a "kink" in it. Grids look like they are warped in near the center. Turns out, that I have a "pinhole" damaged area in the right eye's fovea. It's small enough that the brain can "interpolate" over it, especially when both eyes can see the object.
- CamperBob2 3y agoGee, if only they had thought of this rather obvious point and addressed it in the article.
- qwertox 3y agoI think the same happened to me with LEDs. I have an odd feeling that I can't really see a small section somewhere close to the center of focus, not directly at it. I remember an odd sensation in the eye for days after dealing with a white LED.
- fy20 3y agoAre you sure thats not just the blind spot? It's quite big - roughly the size of a rubbish bin lid on the other side of a bedroom. Here's how to spot it: Hold you hands together, with thumbs up, at arms length. Close your left eye, and slowly move your right thumb away to the right, while looking at your left thumb. At around 6 inches it will dissapear. It's kind of hard to notice when my thumb is static, but it's more obvious if I wiggle my thumb while doing it.
- istjohn 3y agoWoah, that's neat!
- qwertox 3y agoWow, cool stuff! But no, its much closer to the center, and it's not something I can really spot. I just know that it started after I dealt a bit with newly bought "high power" leds. Not really high power and I never really looked directly into them (them facing at me). It also might have been some bright, red ones on breadboards. Happened over 10 years ago.
- AdamH12113 3y agoOptometrists have cameras that can take pictures of your retina and see if there's any obvious damage. You might consider getting your eyes checked out.
- jijijijij 3y agoThey won't see "dead pixels" unless it's severe damage, or a different underlying cause. All bets are off on the optical nerve, since MRI resolution may at best allow to spot a tumor. They can, however, do an extended version of the blind spot experiment above for the whole field of vision, where they project light dots into a hemisphere in an unpredictable but iteratively somewhat exhaustive fashion. Very tiring and challenging test, since you need to keep your eyes from wandering, fixated at a boring reference point for more than half an hour. Like a hearing test, but for your eyes... Laser beams or high energy radiation in general may also damage vision elsewhere in the optical pathway. Like opacification in the cornea or vitreous body when proteins get denatured by the heat. The body is very bad a repairing any damage in the optical apparatus since the eyes do have their own blood barrier, so macrophages usually don't have access to clean up "junk", and most tissues involved aren't really regenerative. Worse, damaged proteins tend to slowly spread the faulty structure to their neighbors. Don't fuck with your eyes!
- solardev 3y agoWarning: Do not touch laser with remaining hand.
- m463 3y agonot that one, the other one.
- rolandog 3y ago> So the last thing I want, is to be near unconfined lasers powerful enough to ionize the air. I wholeheartedly agree. Just thinking about how the potentially-unregulated cheaply-manufactured knock-off projectors will result in having to wear welding glasses when walking around the street to avoid being blinded by the 3D advertisements that are being shot at your face...
- cyanydeez 3y agoUnfortunately, we couldn't even protect the dumbs from staring at a solar eclipse. Safety standards are ridiculously hard to calibrate.
- PhasmaFelis 3y agoUnrelated, how bad is it to look without protection during totality? We got the approved eclipse glasses and diligently kept them on through the whole lead-up, then couldn't see shit once totality started, so we took them off and gazed at the loveliness and then hastily put them back on t moment the sun started to re-emerge. I get that it's not good to tell the public "don't look at an eclipse unprotected except for this precisely-timed period," because that would lead to a statistically significant increase in permanent eye damage, but what we did seems to have gone fine, at least when exposures are circa once a decade.
- LegionMammal978 3y agoThe general advice (at least from everything I've seen) is that you can and should remove your eclipse glasses during totality; after all, the bright surface of the sun is totally blocked. I personally looked into the research on solar eye damage a few years ago (when the 2017 eclipse fervor had died down), and my impression is that all recorded cases result from focusing directly at the sun for at least several seconds straight; glancing very briefly at the sun, or seeing it in your peripheral vision, is only uncomfortable at worst. Eye damage is mainly associated with eclipses since they motivate many people to stare at the sun, rather than the partially-eclipsed sun being uniquely dangerous to look at. But when the time comes around, the messaging gets very black-and-white, as you said. (Not that it's a bad idea to avoid looking at the sun as much as possible!)
- colordrops 3y agoThis article is 9 years old. Probably went nowhere because of the reason you state.
- robertclaus 3y agoLol, I completely missed this. Thanks for the callout. That WAS right around when everyone was trying to (or started to) use gimmicky volumetric displays at the trade shows I attended.
- hi-v-rocknroll 3y agoWhat sort of work? Industrial processes like cleaning or cutting, or physics/engineering bench firing?
- cyberax 3y agoPhysics (well, physics for microbiology), with IR and red lasers. I was pretty diligent with wearing glasses, but apparently not diligent enough.
- eternauta3k 3y agoSometimes there's no way to be safe, e.g. aligning pumped lasers where you'd need one set of glasses for the pump wavelength and another for the final wavelength.