OXFORD, Miss. — Mississippi quarterback Ryan Buchanan straps on a headset that covers his eyes, and instantly, he sees a scene that looks like a video game, all set from his perspective.In about a minute, he runs through a handful of plays, checking his receivers, deciphering defensive coverages and making split-second decisions about where to throw the football.And just like that, practice is over.“I felt like I was in the future putting this thing on — something that you would see on TV shows,&rdquo …