... you can build a light-tight housing and use a cheap web-cam for visualisation.
On the other hand - with the diode pointing down and if you don't place reflective parts into the beam and place your head above the working laser, even the cheapish chinese safety goggles will protect your eyes.
But better check the shielding ability with defocussed beam by placing the goggles into the beam and check, if/what's passing through the goggles onto white paper.
The biggest hazard is not the visible laser light, but toxic fumes ...
Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [
reprap.org] -- Deutsche Facebook-Gruppe - [
www.facebook.com]
Call for the project "garbage-free seas" - [
reprap.org]