Yup , laser safety is of deep concern especially when playing/aligning open DPSS units and short pulse yags.
The problem is when the OD gets up there the visibility is nil , nothing , nada .
My solution that has worked out quite well is the use of video goggles.
This allows viewing of the invisible and visible outputs and has maximum visibility with no chance of eye damage no matter what the wavelength or power output.
They look stupid but work superbly !
Full head enclosure video goggles great alternative !
Dave