SKeijmel, it is good to see you have an interest in safety. I don't have any advice to give on inexpensive safety glasses for green lasers, not yet anyway... I am always on the lookout for them from unexpected sources, but have so far been unsuccessful finding them (this may soon change, I just found another possible 'source'
)
As for the power of the lasers I have owned during the years I
believe the damage was done, I'd really only like to say that it was all over the spectrum... err maybe that isn't the right word... say Wattage range (as well as frequency spectrum). But I'd like to answer your question as asked, so here is what I remember the laser's power was
supposed to be as far as the ones that I owned.
I had a 200-250mW green for about 1 - 1.5 years.
Several 150-250mW reds for at least that time.
2 100+mW violet for about 4-6 mos.
2 50+mW green for 2-3 years
Several 5+mW greens for 4+years
A ~20k-40k+mW infrared for about 2 mos (ALWAYS WORE GOGGLES)
Several 600mW-1.5kmW blues throughout the last 2 years
Please remember, I don't own a meter, so I can't verify powers.
More importantly - ambient lighting conditions, target surface reflective properties and some other factors such as viewing period, spot size, and distance have more to do with the damage potential of a laser than do the power. Also, don't forget, that 1Watt is 1Watt whatever the wavelength, the only difference is that with colors that 'seem' bright, our pupils dilate (get smaller) therefore protect us better. 1Watt of red under average lighting at a distance of 1 meter on a brick will be more damaging than will 1Watt of green under average lighting at a distance of 1 meter on that same brick...
BUT ONLY...
because our eye's built-in protective measures notice that there is a danger MORE when it is green than red (or blue)! (and therefore dilate our pupils)
It is not easy to set simple rules for when glasses are needed, but I will try.
If it is green, and it is bright aka leaves spots, you should use glasses, or at least not dwell on the dot.
If it is red, and it is leaving spots, well, thats quite a bit worse. Red can do damage when it isn't leaving spots in your vision.. If you know how powerful a green needs to burn something BLACK, and you have a red that can burn that same BLACK item similarly, assume you need the same sort of protection you'd need if the laser was green.
If you have an infrared laser (670nm+) you just better f@*n know what it takes to be safe OTHERWISE, DON'T MESS WITH THEM YET!!!
If your laser is 445nm blue, you need goggles for any sort of close proximity spot gazing unless you are REALLY underpowering it.
If you have a violet 405nm bluray laser, you should be wearing glasses for close proximity spot gazing unless it is only a few mW to a few 10mW. In my experience, treat the violets like you do the infrareds. In other words, assume the dot is hundreds of times brighter than it seems.
In all these cases, it is assumed to be in average lighting conditions. If it is darker and you don't have glasses, turn the lights on. Things burn the same no matter what the ambient lighting is like.
The most important thing to remember is that the person that wrote this 'guide' has severe damage because he didn't follow this guide to a 'T'. So if anything, err a bit on the safe side.
One other thing, SKeijmel, is that I dispute the usual belief that it only takes one mistake to be blinded. I have caught momentary (~10-50ms) direct exposures from a couple hundred to thousand mW, usually involving letting a friend 'try out' the laser and an unfortunately placed mirror. It hurts, it can cause headaches for days, it causes swelling even. But if you'd have asked me a few days later if my vision was worse, I'd have said "I ... don't ... think so?!?":undecided: In the end, I really wouldn't have noticed. But make no mistake, the damage was done!
Here is a comparison: Go stare at the sun!
No, don't. If your instinct is 'damn, that's bright!' Then stop it.
I have a feeling that lasers lose their appeal when you are blind.
So sorry for the really long post. I tried to be concise!