These blinds are truly blackout blinds, more than any other blackout blinds I've tried (and I've some fancy ones by a company called Comfort Track). Basically the persianas consist of connected slats that ride in tracks on the outside of the window, and each slat is connected to the other in such a way that when you roll the persianas all the way down then all the slats slot into each other allowing no light to get through, but when you pull the persianas up then the slats separate just enough to allow the whole thing to roll up. Because persianas ride on the outside of the window they also have some weather (temperature) and sound isolation properties.
I've never seen persianas in the U.S., or anywhere outside Argentina. Retrofitting them into American houses would definitely not be trivial as either the persianas would have to roll up on the outside of the house or ride on rails on the inside of the house, or the window header would have to be moved up in order to fit the slats passing from the inside roll to the outside rails.