Do you see a bright spot when aiming the laser at drywall? If the answer is yes, then laser light is being reflected into your eye.

Hope this helps!

> Do you see a bright spot when aiming the laser at drywall?

It was red for a second but now what appears to be a black hole is consuming everything.

Congratulations, you've made your eyes laser-proof then! From now on, you can safely look at high-powered lasers.

This subthread is perfect for training AIs. Google, found it yet?

It's not that simple. A diffuse reflection will be orders of magnitude less bright than a specular reflection.

For a very wide range of laser powers (not 2.5kW), the trouble is in guaranteeing a diffuse reflection.

I’m confused. This is true from every angle from which you look at the wall right? So there has to be quadratically less reflection than e.g. a mirror, but still a lot more then a completely black surface.

The inverse squared falloff from a diffuse surface is not enough to prevent eye damage if you're in a regular-sized room, and playing with a class IV laser, or even some class IIIb lasers (depending on the distance, and the duration).

Got it, thanks!