It mostly affects your direct field of vision and will leave most people with only or at least stronger peripheral vision than direct forward vision. Your main field of focus will be very blurred or completely gone but it varies person to person.
My grandfather was diagnosed in both eyes in his mid sixties I believe. He lost the ability to do some things effectively but learned to live with it. A few years after it began to affect him he still managed to pick off a groundhog between the pickets of a fence. I guess he turned to my grandma and said, "and they say I can't see". He really was limited of course but somehow compensated to line up those sights and was very pleased with himself, as he should have been.
Sorry for the crap news but stay as positive and as healthy as you can. I know there are some treatments available and of course they advise vitamins but what kind I don't know. It's always been a concern for the later years in my family but maybe it will skip a couple generations.