Need suggestion about laser power

Happy new year to all, it is the beginning of my spring classes, I'm at my final grade year in mechanical engineering in which many presentations exist, I was wandering if I can use one of those laser pointers shown in the video below in my presentations, I'm afraid of their actual power. As you see in the video, the white laser is claimed to be 1 mw, the key chain laser is claimed to be 5mw lasers, but no one can tell the actual power, I experienced a direct exposure beam from the key chain laser twice and nothing happened as my eye blinks instantaneously, what is the suggested power from the video and is it safe to use it In my presentations ?

Finally, I was able to measure the power of the laser pointers, I went to my physics lab professure and he measured the power of both lasers and the power was found to be 7mw and 9 mw for the white pointer, key chain respectively. The professor told me that if I didn't look directly at the beam, I should be fine, and there are no need for safety glasses unless I want to shine the beam to a reflected surface like: mirror.

moh17 said:

Finally, I was able to measure the power of the laser pointers, I went to my physics lab professure and he measured the power of both lasers and the power was found to be 7mw and 9 mw for the white pointer, key chain respectively. The professor told me that if I didn't look directly at the beam, I should be fine, and there are no need for safety glasses unless I want to shine the beam to a reflected surface like: mirror.

Click to expand...

You can look at the lasers beam without a problem, shinning it around mirrors though is when safety glasses should be used(as said by your professor) & anytime these are used around the house, where other people might cross the beams path. Safety glasses are required since these can cause eye damage before your eye reflex kicks in.

-Alex

Tha Greenlander said:

You can look at the lasers beam without a problem, shinning it around mirrors though is when safety glasses should be used(as said by your professor) & anytime these are used around the house, where other people might cross the beams path. Safety glasses are required since these can cause eye damage before your eye reflex kicks in.

-Alex

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Thanks, I see small circles, sometimes different shapes while reading, looking at white objects or walking. I'm afraid it's from the laser, I have never had a direct exposure except for one time in my left eye which I have no problem with this eye, only with my right eye. I searched Google and found eye floaters which seems to be my case. for my knowledge what is a blind spot ? , how you feel it ? ; what is the difference between eye floaters and blind spots in terms of the feeling ?
Thanks,,

I got floaters too, their just a mild annoyance to be honest nothing to worry about too much. A blind spot AFAIK (regarding lasers) occurs when a high power beam hits your retina burning the light receptor cells in that spot. The damage is unrepairable so you basicly wont be able to see in that spot. Your brain fills it in though usually so you probably wont notice it unless you really try to but it'l basicly just be a black area in your vision wherever the laser hit.

moh17 said:

Thanks, I see small circles, sometimes different shapes while reading, looking at white objects or walking. I'm afraid it's from the laser, I have never had a direct exposure except for one time in my left eye which I have no problem with this eye, only with my right eye. I searched Google and found eye floaters which seems to be my case. for my knowledge what is a blind spot ? , how you feel it ? ; what is the difference between eye floaters and blind spots in terms of the feeling ?
Thanks,,

Click to expand...

Not a lot of 'feeling' in the traditional sense as we dont have much in the way of pain receptors in our eyes..

blind spot -- We all have one in each eye-- its the place where all our eyes receptors (optic nerves) leave the eye and go to our brain-

to illustrate this place to pea sized dots on a piece of paper about 6 inches apart- stare at one dot with ONE eye closed- move the paper at at one distance the other dot will NOT be 'there. The reason we dont see amythink missing is because our brain 'fills in the missing spot- so if you are looking ay a say- brick wall there will be no bricks 'missing'..


This fact surprized me a lot-- our eye's lens IF hit driectly staright on can magnify the laser much like we do with a mag. glass and the sun.
The result is said to be 100,000 times higher ( some say 200,000)
so even in the very short .25 seconds we take to 'bilnk' or 'block' the laser, enough power can be made to cause injury- SO avoid level line lasering --especaillly anywhere between your belt and the top of your head or more)-- for laser shows all beams must NOT be lower than 3 M or 10 feet from ANY place a viewer may enter. (like a girl on her BF's shoulders)


hope this is helpful and accurate--Hak