I looked this up for a laser-based projector, Class 2 is "blink reflex should protect you" and "don't be a doofus and stare into it for a long time". Look up the classifications on the google and you'll see other things like "don't look into the rays with a set of binoculars" and stuff.

Class 1 is pretty darned safe, but if you're continually bathed by 50 passing cars an hour while walking on a sidewalk... pitch it to a PhD student you know as something they should find or run a study on.

I have a Class 1 Makita (green) laser level, wide strong beam, excellent tool for landscaping. I accidentally looked into it from a 10 cm distance. It did not leave permanent damage, but for a few days I had the dot burned on my retina. And yes, I almost immediately closed my eye - within a few hundred ms's.

Don't look into the laser with the remaining eye