laser safety question

[TheBeam]

I know looking into a laser is a bad idea. Therefore shining one into a mirror and looking at it would be bad too.

What about just shining it on a wall and looking at it? It still is being reflected, not absorbed.

 

[FlashlightOCD]

It is still being reflected, but in several different directions [180 degrees]. Unless you're talking one super heavy power laser then looking at the reflection off from the wall should not be a problem.

A typical laser pointer is designed to bounce off from a non-reflective surface without causing eye damage.

 

[TheBeam]

That sounds right, but now that makes me think about the mirror. Would looking at the spot in a mirror be ok as long as it did not reflect straight back in my eyes? /ubbthreads/images/graemlins/cool.gif

 

[The_LED_Museum]

As long as the laser beam doesn't get in your eyes (directly from the business end of the laser or reflected from the mirror), you can shoot it at a mirror and observe the reflected beam going over your shoulder or whatever.

 

[RevDavid]

A friend of mine was goofing off with a fairly bright red laser several years ago, and he shined it directly into my left eye. It was only there for a split second, but was extremely startling and unpleasant. I saw what I could only describe as brilliant red sparkles in that eye, and there was a physical sensation... hard to describe, but it was almost as if I had been poked gently in the eye.

It scared me, and I thought he had damaged my eye, but I did not seem to have any lasting effects. I would not like to have it happen again though.

There are lasers now that are probably far more powerful that people are playing around with than that one. I am glad it was not one of those high powered green lasers.
Best bet is be careful. I was shocked at just how intense such a small light source is. I would rather take a peek in the business end of an M6 than peer into one of those things again.

David <><

 

[mattheww50]

The threshold of danger is generally accepted as about 5 milliwatts, which is class IIIa. Looking directly into it is not recommended, but short term exposure is unlikely to do any permanent damage. However once you get past 5 milliwatts, into a class IIIb product, which can be up to several watts, the risks or permanent damage are very real, especiall with IR lasers, where you cannot even see the beam.

This is why laser pointers for sale to the general public are limited to 5 milliwatt, IIIa products.

 

[sc1276]

in the lab down stairs they use a spectraphys NdYAG, thats about 2meters long. apparently its powerfull enough to fry you eye faster than your blink reflex.
nasty

 

[INRETECH]

The best answer to all these questions is be EXTREMELY CAREFULL, we only get one pair of eyes for life - why take chances; otherwise you will have to live with it for the rest of your life and our sight is one of our most precious senses

 

[TheBeam]

Ok, one more question. My son wants a laser. He's not stupid enough to look in the end of it. I'm assuming that a day or two of playing with one would be ok. What about many years of looking at the reflected spot on a wall? Wouldn't this add up to damage? How much of this spot on a wall can someone take?

 

[FlashlightOCD]

How mature is your son? I would not consider a laser pointer a child's toy or even trust it in the hands of an immature adult. I work with an idiot [30+ years old] that was having fun aiming a "tuned" 5mw green laser pointer at somebody's ear, if that person had turned their head toward the idiot they could have easily gotten a direct hit in the eye.

To answer your question: I doubt looking at a spot of a common laser pointer on the wall will damage your vision, even for extended periods.

PS: You might also look for a very low power red pointer [Class II], they are much safer.