If you’re using the laser cutter in an open mode please, please, please make sure it is sealed so that no light leaks out of the container. The CO2 laser is in the infra red spectrum and is invisible to the eye so the case has to be sealed. Making things worse, our walls are white, any light that leaks in to the room is going to get bounced off the walls, so it’s not just a danger to the operator.
It’s just like welding – if the light can hit your eyes you’re going to suffer damage. I’ve worked with people who have had welding flash injuries who were simply standing in the wrong part of the room while others were welding.