Part of my left eye is blind, is this a symptom of becoming blind?

There's a strip of blur across my left eye. It's hard to explain but I can't see anything out of it, it's like a small part of my left eye is blind, I can't see anything from that part of my eye, reading text is hard and the first letter of any word usually doesn't seem to appear when I'm looking at it. Is this a symptom of blindness? I looked it up but they all said it's just gradual blurring until your eyesight is gone. Nothing seems to fit my case, I found very few with this problem and very few answers to it.