Short answer: don't look at a laser light.
The thing about lasers is the total exposure. I took a class many moons ago where we went through the calculations where you take the power level of the laser, wavelength, any coefficient of reflectance and duration of exposure. With all that, it amounted to - don't look at it. The real danger is that laser light is "coherent" which means all the photons are in lock step, which makes the light MUCH more powerful than regular light of the same wavelength.
That being said, I of course don't always let good sense stand in my way. I own and have played with many lasers over the years. If you're dealing with something on the order of 3-5mW, then you could maybe get away with glancing at a beam (on the order of a few hundredths of a second). If you shine it on a non-reflective surface, like a painted wall or wood, you can look just a little longer. What you see is a geometric structure. I learned back then that the structure you see is that of the rods and cones of your eye, not any actual structure in the beam.
I would advise against doing any of that with anything of higher intensity than 5mW and shining any laser on reflective surfaces is dangerous because: First - It's difficult to control exactly where the various facets will reflect to. And Second - The intensity isn't attenuated enough to make it much different than looking directly into it.
I think one of the Spooky Cold Lasers is greater than 5mW, so be careful. I suppose you could start with a welder's helmet and work your way from the darkest to lighter until you find something that works for you. Keep in mind the power over time thing with maximum exposure though. If you see spots, you're probably going too far.
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