Hi,
It's funny how anxiety takes particular forms. On this site, I've noticed a few people who specifically fear schizophrenia.
Vision is actually much worse than we think it is because the brain fills in the missing information for us. In short, vision is good in the actual direction we are looking in, for example you can only read looking straight ahead, but then our vision gets progressively blurred and useless towards the edges of our sight. We aren't normally aware of how bad our peripheral vision is because we are so used to turning our head to see. You have become aware of it.
Edit: OK, I've just read why you have the anxiety, because someone in your family has schizophrenia.