I'm no ballplayer, nor do I play one on TV. But though I don't have to recognize the spin on baseballs coming at me at 132 feet per second, I do depend on my vision for my work quite a bit.Basically, I spend most of my waking moments staring at small type on a computer screen. And sometimes, staring at even smaller type on my cellphone.  And at night, I go back and forth between staring at the small type and images on a TV screen. Food and shelter for a family of five largely depends on my ability to perform these tasks and then move my fingers on a keyboard while I do it.Historically, this has been as easy as blinking. But in this, my 43rd year, it has finally gotten more difficult. I look up from looking down for a while, and at first the TV is blurry. I look down from looking u