Before the advent of Powerpoint and even the PC, in the era of plastic “foil” called Vugrafs, when the speaker narrated it, the high power laser pointer was used to direct the audience’s attention to the various parts of the “slide”. Since then, we have started to animate and have a pointer that can be controlled with the mouse. Laser pointers like this are now less and less used.
In the early days, lasers were connected to sensors on projection screens. If the laser is not scattered from the screen, it will immediately turn off. In this way, the audience is protected from the stray laser pointer beam. As more and more companies use Class 1 lasers, people no longer believe that it is necessary to protect the audience because the risk of eye damage is small.
Nowadays, “green laser pointers” are mainly dangerous toys bought by the rich. Except for scientific experiments or demonstrations, almost anything you might want to use them is illegal. I bet that most people who own laser pointers use them for pranks.
It is illegal to point them at people, occupied public places, occupied vehicles, occupied houses, airplanes, or any satellites. You don’t need 500 milliwatts to play with your cat. 500 milliwatts can burn wood, paper and other objects that are easily ignited. Think about how even the diffuse reflection of a piece of paper affects your eyes.
There are legal laser shows. In the hands of well-trained professionals, higher power blue laser pointer can be used safely. Today’s laser pointers should be respected like guns. I haven’t used any of my laser pointers for a long time.