New Batteries Dangerous

Hey, I ordered a 5mW Ebay laser. A few days later (today) I bought Energizer E2 Lithium batteries (AAA). It made a HUGE difference, probably 4 or 5x brighter. I set it down outside at evening and walked away to see how well the beam showed up. 20 feet away, I could see the beam perfectly. Very impressive. ;D Anyway, I was about to walk back, and I got hit in the eye. It didn't hurt, but for the next 3 minutes there was a grey blob when I blinked a lot. It also kind of felt like my eye was watering a little. Should I get goggles? I had no idea batteries could make a 5mW so dangerous. Thanks.

It's probably putting out more than 5mW to begin with.  My 5mW Newwish greenie is putting out almost 20mW. However, even with a low powered laser you should avoid looking into the beam.  You should avoid getting your head even close to the beam.  If the beam isn't visible enough, get a higher powered laser (and goggles) or add some "visualizer" to the air (incense, deodorant, hairspray, etc.)

Learn from this close call.  You rarely get second chances with your eyesight.

Peace,
dave

Really? I always heard Ebay lasers were <5mW. But do I need goggles? Would shining it on a white surface or stray reflections cause enough damage for goggles? I wouldn't have thought it would be that high. :-/ And I've always heard the non-goggles limit was 30mW. If it's seriously putting out that much power, should I be concerned about an IR filer? Thanks for fast responce.

it all comes down to what your eyes are worth to you!

randomlugia said:

Really? I always heard Ebay lasers were <5mW. But do I need goggles? Would shining it on a white surface or stray reflections cause enough damage for goggles? I wouldn't have thought it would be that high.  :-/ And I've always heard the non-goggles limit was 30mW. If it's seriously putting out that much power, should I be concerned about an IR filer? Thanks for fast responce.  

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Naw. The cheap lasers on eBay are fine. It's the "high powered" ones that are never up to spec. The only surfaces you would need to be concerned about are smooth, shiny surfaces (mirrors, crystal, etc.). A momentary hit off of a normal surface in a house with 20mW usually won't do that much harm, but you were placing yourself intentionally in line with the beam. My advice about goggles was that if you wanted to see the beam better, get a higher powered laser and some goggles (or just use a visualizer). Use the goggles to get the laser set up with the "spot" in a beam killer and then take off your goggles and enjoy the beam. If you are avoiding the green beam you are pretty much avoiding the IR beam as well. However, IR light spreads more quickly than the green beam. If you are getting your eye close enough to the green beam to be hit in the eye, you are definitely exposing yourself to the IR light leaking from the pump diode when you get close to the green beam.

Peace,
dave

uh oh i stared at a 300mW red laser beam like 2 feet away
but it was on black cloth but then reflected off a polished wood surface
my vision kind of blurry

The IR output from lower powered greens is usually nothing to be worried about , its usually no more than 10-20mW from a 5-50mW pointer, and as dave says it diverges rapidly .

Ok, that makes me feel safer. ;D But I've never heard the term beam killer before. Can someone explain?...