no, I'm not in any sort of technical profession. I'm in business school currently. So I'm pretty good with researching, finding numbers and figuring out what they're supposed to mean. this stuff is out there on the internet.
as for getting hit with a shotgun blast:
"It is generally accepted by those involved in the wound ballistics field that a minimum penetration of twelve inches of 10 percent ordnance gelatin is one of the criteria needed to provide reliable incapacitation of a human assailant."
quoted from above site about Combat Shotguns
they have the data for #4 Buckshot (like the ANSI test) listed @ 7yds to be between 9-11 inches. I'm fairly certain that this refers to a center-mass shot and not one directly to the face.
so you country boys who get shot all the time: make sure it's no bigger than #4 Buck. OOO Buck moves you into the 14-16 inch range which, in the head or not, means you've got bigger problems than your eyes to worry about.
here's the requirements of ANSI z87.1:
http://www.titmus.com/ansi_whitepaper.htm
pay attention to the right side, as it entails the latest version of the testing requirements, updated from 1989.
If my numbers aren't to anyone's liking, I'm sure one of engineers can enlighten us further.