Hello Darkness: My doctor said, "Son, you will be blind tomorrow."

Imagine you are back home from college. It's a beautiful summer evening, and you're pitching in a baseball game when suddenly you can't see the batter, your catcher, the mound beneath your feet. Sandy Greenberg recovered from that moment, but six months later, in the middle of a final exam, he went blind for good, and forevermore.

A junior at Columbia University on a full scholarship, Sandy had just started to see the world open up to him. But instead of his plans for a bright future, he now...