Alright, the machine I am talking about  involved flashing lights into the eye while a loud bang similar to an old MRI machine comes with the flash. I remember telling the staff with me that the process was annoying, but I had feeling some people would get angered by the whole thing. Not sure though.

Does anyone know what it is called? What was it for? Factual answers only please, I don't want anyone to get triggered or worry.

&amp;#x200B;

What was like for you if you experienced it?

For me I had to try to not ask the staff to stop. Of course, I knew they eventually would but the sound

and the bang was something else. I never got a straight answer when I nicely  asked what it was for.