A Practical Guide to Lasers for Experimenters and Hobbyists

Absolutely! It's so good to see real HTML used to organize substantial information, instead of the high-glitz low-content stuff we see so often these days...

Its all about how much energy hits the eye, and for infrared lasers you can't assume someone will blink, so you cant use short exposure times.

From the paper, they are pulsing the laser, so the laser is hazardous out to ~1.5m. Pg 5 of their paper goes into detail on the calculations one needs for laser safety.

It seems like they used 100mW IR explicitly so they could use the platform outdoors. In most cases, you're fine looking at the reflected (usually diffuse) light, but you shouldn't stare into the beam. If you're working indoors you should be fine with visible low-power lasers, e.g. 1mW red or green.

There are numbers in the paper (linked in the article) and they explicitly calculate the power vs the safe threshold. They basically say you shouldn't go closer than 1.5m to the device in operation. They give some suggestions to improving that, but it doesn't look like any of them were actually implemented.

There have been many developments in laser technology and many updates to the page since then - check the version history (unfortunately missing dates) and you may spend a few more hours!

http://www.repairfaq.org/sam/lasersam.htm#samver

I have to admit I look back at sci.electronics.* and comp.robotics with a lot of fondness.

I've spent time on Sam's FAQ even when I was somewhat older. :)

Lasers and the "Holography Handbook: Making Holograms the easy way". It had xkcd style drawings back in the 80s.

My go-to was Britney.

http://britneyspears.ac/lasers.htm

Everything except the edge-to-edge text. Put that in a container!