I know that if you shine a laser in your eyes you go blind instantly.
But is there any risk in blinding yourself if you look at a powerful laser from the side?
I mean, like you hold it in your hand and shine it at a wall and just look at the ray of light and the wall.
Laser power is between 3 and 5 W and the laser is blue and it burns stuff.
They say, that you can look at the laser 2 times. One time with left eye, second time with right eye.
Yes, with even 1/100th that sort of power there is a very significant risk to small accidental reflections hitting your eye. I wouldn’t consider a 1W+ laser indoors without proper eye protection for even a split second. Retina damage is also cumulative so you won’t notice even the smallest exposures adding up until it’s already too late.
I have a 1.5w (1500mW) blue I use for star gazing, or pointing out areas in the sky. Hard to do that with filter glasses on. I treat it like a gun, and always point it in a safe direction. Also, as a private pilot, I’m very aware of aircraft. But where we are, aircraft are not out late at night, and rarely see commercial aircraft crossing the sky. I have a 4.67mW green thats pretty cool, but has to be pretty dark outside.
But yeah, cumulative retina damage is real, and common sense is a must.
Ok, but assuming there are no reflections, there are no way you can get your eyes damaged, right?
I don’t think a concrete wall can reflect the laser, and even if it did a little bit, what are the chances that it reflects precisely in your eyes?
I don’t know man, I don’t shine the blue laser at any objects. Just directly in the sky. This guy has a good comparison using a 10w adjustable 445nm laser on various goggles. He can adjust it from 5, 25, to 100% power. Looks like he’s 30 or so centimeters (or 1 foot) away.
Spoiler, 100% (10 watts) power, burns all of the goggles instantly
Read through some of the resources on LPF. If you can see the light that means there is a reflection. Without a perfectly smooth, flat, consistent surface those reflection can hit a spot that focuses the light a bit. If the wall is painted that is absolutely not something you want to be shining it at, and anything at “indoor” ranges is not a good idea at all.
Additionally remember that 5mW is basically the “safe” limit to shine around - but NOT to look into the beam of. If your laser reflects even 0.5% of that light back at your eye you’re already being hit with light far in excess of the total power of a regular laser “pointer”, which again is not safe to shine in your eye.
Another reference:
Wrong. If the laser is strong enough, just looking at the dot it makes hitting something, including concrete, could cause instant permanent eye damage.
This x100
Your vision is not something to lightly gamble. Read: “PERMANENT”.
Wear goggles. Use outdoors only. If you have to ask, you probably shouldn’t do it.
Thanks Guys, Lasers are off my shopping list, permanently 
Good one sp5it!
if you really want to look, look thru a camera with LCD viewfinder, and duct tape the other eye shut, lol,
You can buy 5mW in any wavelength and they’re completely safe! Even 20-30mW green lasers are very impressive outdoors (as bright as blue/violet/red of MUCH higher power) and while you should still be very careful with them they aren’t the instant cold sweats kind of dangerous like 1W+ units are.
Ever since i saw a home built portable high power laser video on youtube i think about some crazy person blinding 1000’s of people from far away.
Yep, anything is as dangerous as you make it. My 5mw green is fun, but you still wouldn’t want to hit someone in the eye at close range.
5mw green
1500mw blue
Proper laser safety glasses (never ever trust the ones the laser came with) are mandatory. The others are right, even the reflection of the spot can damage your eyes. They are not toys. You only get one set of eyes.
There’s a guy styropyro on youtube who knows what he’s talking about. He builds lasers and such and did a demonstration of cheap vs properly rated laser safety glasses (there are different types for the different wavelengths of laser light). If you need a reason why to get good ones of you mess with high power lasers look that video up.
I thought I was the only person who worried about this, it’s probably an irrational fear but completely agree it’s terrifying to think about. Also the idea of pretty much anyone being able to buy these lasers off AliE or similar and having ZERO safety information is going to cause injuries and absolutely shouldn’t be happening. High power lasers should be kept to specialty sites IMHO.
Here’s Styropyro’s laser eye-pro vid:
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I will take this as good warning. I don’t fly anymore either, especially since working 4yrs in Aviation. 
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You do know the stats about Aviation accidents ? Poor maintenance plays a higher % than you may be comfortable with.
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