There are a some members of PL that do Laser Projector shows
that are safe. IIRC there is a MPE calculation that needs to be made
with a Photodiode... Oscilloscope and Power meter through a 7mm dia.
aperture (to mimic the human pupil dilated in a darkened room).
Then that data is used to calculate the MPE value of that particular
show...
BTW...MPE stands for Maximum Permissible Exposure..