Driving blind

I remember when I first started riding with my father and watching him flash the headlights on-off when a truck had passed him on the highway to signal the "all clear". Something has gone wrong......
First, a little history about this concept......Back in the golden age of trucking before the mega truck stops and interstate highways, the trucks were equipped with a small round mirror on a straight stick mounted off the roof line. These were nick named "lollipop mirrors" because it resembled a child's lollipop. Now these mirrors were just about useless going down the road because they vibrated so bad there was no way to see what was behind you.
So, to combat this problem, the drivers came up with an unwritten code to help each other out when passing. During daylight switch the headlights on, then back off. At night, turn the headlights off for one second and then back on again. This did wonders because the passing driver could see a vague shape and might not have been able to see the truck being passed or the end of his trailer, but could see the flash off the lights on-off or off-on.
Who is the idiot that decided that flashing the high beams at a passing truck was O-K?  Is this being taught at truck driving schools? Company traing schools? (It seems like 99% of the time it is a company driver doing this).This is so dangerous that it is hard to belive it actually happens every night. When some moron does the high beam flash to a passing vehicle, the passing driver is now "DRIVING BLIND" because the driver being passed just blinded them with the high beams. Let me explain, when night driving the pupils in the eyes are widely opened to allow the most light in (like a cats eye), when a bright light hits the eye, it causes the pupil to constrict very rapidly and the brain has to play catch up before the vision comes back into focus. During this time the driver might travel 200', 500' or more completely blind!!! HELLO!!!! THIS IS A STUPID THING TO DO TO YOUR FELLOW DRIVERS!!!
IF a truck is equipped in such a way that the headlights can not be switched on-off, or off-on. PLEASE, DO NOTHING !!!!! I can see the end of my trailer and I can see your truck in my mirror. I do not need your help when passing your truck. I have come to the point that I no longer even flash my lights at other drivers and ignore them when I am the one doing the passing. AND to the idiots that keep flashing the lights at me if I do not switch lanes when they think I should, "I am driving my truck, I will decide when it is safe to come back into the lane in front of you. AND I am responsible for the safety of my truck, not you....."
This "High bean flashing" has got to STOP!!!! Even though you drivers think you are being helpful, your not. Some where down the line someone is going to die because of this practice......HMMMMMM, maybe I could get a grant to study this problem.