Most people love lasers, because they can make cats chase, read music from a shiny disc, etch and cut materials, and be very shiny in Hollywood blockbusters, even when their presence makes zero sense. That said, lasers are also extremely dangerous, as their highly focused nature and wide range of power levels can leave a person dazzled, blinded or dead from direct and indirect exposure. A lapse in laser safety was how [Phil Broughton] ended up with part of his retina forever marked, as he describes his adventures with an overly enthusiastic laser company sales person.
It didn’t take much, just this sales person who made a really poor decision while trying to please some customers and nearly ended with multiple adults, a local school, pilots at a nearby airfield getting their retinas blasted out due to an absolutely harebrained idea to use a fairly high-powered Quanta-Ray Nd:YAG laser on reflective surfaces in the open.
This was in 1999, and fortunately [Phil] only suffered some fairly minor damage to his retina from the laser beam reflection. What happened to the customers (who wore argon laser safety glasses) or the sales critter (who left soon after) is not described, but both may have received some bad news when they had their eyes checked shortly after at the ophthalmologist.
These kind of stories are a stark reminder that laser safety is not optional. Lasers producing a visible (400 – 700 nm) wavelength above Class 2 should only be operated in a fully secured environment, with safety glasses for the appropriate laser wavelength. Class 2 lasers producing a non-visible wavelength can cause permanent damage because the blink reflex of the eye does not offer any protection here.
As even some dodgy laser pointers are being (illegally) sold online are actually Class 2, this should make it clear that laser eye injury can happen to anyone, and it only takes a second to change someone’s life forever.
TL;DR – DO NOT LOOK INTO LASER BEAM WITH REMAINING EYE!
This was the sign we had on the door to the lab where we worked on CD/DVD drives. Yay for IR lasers…
Also, the blink reflex does not work for everyone…
The laser safety classification is based on how much damage can be done before you are even able to blink.
You can do damage with lower-powered lasers if you’re persistent enough, but the higher powered ones are guaranteed to beat your blink reflex.
I had a dog the liked to sneak up besides your head, then lick your eyeball faster then you could blink.
Felt funny.
He also helped keep the cat litter box clean.
++good.
It is odd that for the loss of $250k equipment, damaging the eye of the LSO, VP car destroyed and whatever else may happened, the responsable biped was not given a nice pimple removal with similar laser.
I am building a laser even more dangerous: https://www.youtube.com/watch?v=6w8p3fl4Q1k
I missread your name as Markus Blindhammer.
You should start a career as a comedian.
I’ll never look at lasers the same again
(chuckle!)
It sure opened my eyes (cough) to proper uses of VR goggles. No direct optical path, no problem. Just some messed-up camera modules.
I worked in eye care a few years back and a teenager came in once who’d had a staring contest with his science teacher’s stolen laser. He did both eyes while he was at it. I did some retina scans (ironically with a Heidelberg OCT laser) and they were pretty cooked. He’ll have missing spots (scotomas) in his vision for the rest of his life, but the scariest part is that his young eyes healed enough to legally drive.
The ability of the retina to regenerate is pretty wild. Below are two papers illustrating the potential for partial or full recovery over only a few weeks, but of course it depends on how deep the photo-coagulation damage is. Of course this only applies to microscopic damage sites.
Check out Figure 6. Retinal Rejuvenation Therapy:
https://www.scirp.org/journal/paperinformation?paperid=85424
lost a link there.
https://www.researchgate.net/publication/262693770_Therapeutic_Effect_of_Bone_Marrow_Mesenchymal_Stem_Cells_on_Laser-Induced_Retinal_Injury_in_Mice
Yeah! This guy was already pretty fibrotic in both foveas, so it’s gone, but there’s such great potential especially for congenital issues.
I absolutely would have sued that company into the ground.
I’m not usually a fan of safety officers, but I think he was in the right about this one. That was beyond stupid. How hard is it to build a plywood box, or bring a chunk of asphalt inside? The fact that it was even possible for a powerful beam to shoot out of this thing at such unexpected angles is ridiculous.
When I worked for NCR (National Cash Register) in the 80s and 90s, I was trained on the early grocery store scanners (model 784). Those used he-ne tubes that through a beam splitter and an array of small mirrors projected a “star” pattern made up of parallel lines through a plexiglass window up to the item that was passed over it. This was known as a 1D (dimensional) scanner. To align the mirrors a piece of onion skin paper was place on the window and Allen screws were turned to move the mirrors into alignment. I serviced a lot of stores and plexiglass window replacement (from scratches) and mirror alignment was a weekly task. While the onion skin paper kept the beam pattern diffuse the constant exposure of staring at the pattern makes me wonder if that added to my vision problems over the years. Cashiers in the early days were worried that as they passed the items over the scanner they could receive skin burns or even cancer which was unfounded. Modern scanners now use a laser diode and a spinning mirror assembly called a “wobulator” to project the beams through 2 windows resulting in a 2D scanning of the item (NCR 7878). The integration of a scale into the scanner saves space and adds to the fun of servicing a scale/scanner. I was a state certified scale technician and had to maintain linearity of the scales weight sensing up to 30 lbs and was required to check them monthly and lock out and repair any out of spec scale/scanners. The self checkout scale/scanners these days are supposed to be self adjusting, self zeroing but are no longer tested on a regular basis ( just think about it ).
I worked in two high power laser labs, one mostly UV/excimer, the other doing ultrafast chirped visible stuff, and in both labs, there were PhD’s who were careful with their work but had eye damage from exposure. They were all freak accidents: a capacitor bank for an ArF laser discharged when it wasn’t supposed to and sent a single pulse out when the equipment was in theory not operating, a visible beam found a specular reflection off a chrome plated screw head and got in between someone’s cheek and their pretty well fitting laser glasses, stuff like that. It was mostly because we were using equipment that was transitioning from R&D to production, so the equipment didn’t have full enclosures and we were using curtains and other portable enclosures for protection. But after the third time someone got minor eye damage, I bailed on that field and headed into electrical engineering as my long-term career, because I really like being able to see stuff. Just seems too problematic.
I was describing being puzzled why I went entirely blind, for a few minutes, in a Fry’s Electronics twenty years ago and my partner suggested I had gotten flashed in the eyes with a handheld laser. Oh yeah, that’s what it was.
I came across a brilliant green path on the deep playa, stretching off into the desert on one side and back into a music camp on the other end. A galvanometer or such for a high powered laser had failed with no effective physical safety. I turned my back to it and walked until either turned off or rose into the sky again.
The long-range potency of a laser and the shortness of its action made Burning Man a target rich environment, but it wasn’t until 7 years later when staff got permanent eye damage that BM banned handheld lasers. I wonder how many times it had happened before that.
On simple phrase, “Hey, would you look in there for me?”
Being totally blind in my left eye and legally blind in my right (nothing to do with lasers) I won’t go near any type of laser. As far as I’m concerned, a laser is as damaging to your eye as a bullet is to your brain.
I may not have 20/20 vision, but I would like to keep what little I do have thankyouverymuch.
Obligatory reminder that Steve Wozniak was the original laser safety officer, complete with eye patch.
https://www.geekculture.com/mt2/archives/2018/02/wozs_laser_safe.html
A mandatory read for green laser pointer owners:
https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=906138
Thanks, very interesting. Didn’t know that green laser pointers could emit dangerous levels of IR radiation.
For some experimental power graphs from an old project of mine:
https://forum.arduino.cc/t/laser-power-5mw-or-1mw/1031281/19