That, oh KreepKreep, is something you're just going to have to practice. Here is something I learned that may help with that focus.
Practicing visualization. Stare at an object and only at that object. Learn the details about it; pick it up and look at it if you want. When you think you have the image in your head, close your eyes and recreate it in your mind. Start for short periods of time and extend it. Create your own goals, but maybe going for about 10 seconds to 15 to 30 to a full minute. It doesn't necessarily work for everyone, but it's worth a shot.