I don't know how to GET it, but I used to HAVE 20/10 vision. I could see at 20 feet what a normal person would only see at 10 feet. They usually don't test you past normal vision unless there's a reason.
I have a copy of IE, but to use it I would have to load an obsolete operating system! I use Firefox, but also have Safari, Opera, and Camino ready if needed. So far, I have only had to switch once, to Safari, because some new site wouldn't allow Mac users to enter with anything else. That site is no longer with us.
If I folded t-shirts that way, it would take all day to do the laundry. I grab the shoulders with both hands, fold the sides back and lay it down folding it in two vertically on the way. Much faster!