Smoking can do lots of things to your body, including going blind. But the fact that they probably didn't clue people in on is... It takes a really long time for that to happen. It's like eating fatty foods, you don't get all the health repurcusions right away, and if you do other things to offset what you are doing wrong, it may never happen. IE, If you smoke, but also go jogging, swim, or in some way excercise, the odds are very high you will not go blind.
So what is it about smoking that causes blindness?