[0] Which to me has always been one of those "hard to believe things" and, indeed, I've never worked with an IR laser or tested this (nor would I be interested in doing so) but I can't think of something more terrifying (related to blindness, anyway) than walking into a room, looking at something, seeing nothing particularly interesting and then ... seeing nothing at all ever again.

To emphasize this point, since we're talking about a 450nm laser at either 500mW (maybe just barely low enough to hypothetically qualify as Class 3B?) or 800mW (probably Class 4?), any stray reflections could easily cause blindness before the eye can respond by blinking.

Any laser powerful enough to burn or cut is a "why did my eye make a popping sound"[1], risk, not the "blink oww! that's bright!" that we are familiar with.

[1] the sound is a spot on the retina explosive boiling after the laser heated it extremely rapidly past 100C