Hi Steff1990!
I have somewhat of an idea of what you're talking about. I have OCD, but I've always had poor concentration throughout my life. There have been times my mom has thought I've needed my vision checked. I've definitely had significant blurriness in my vision, similar to what you're experiencing.
But I realized in bed one day that I could actually correct some of my poor vision. Since I believe it's primarily mental and not physical (or else the doctors would have found something), you can adjust your vision. Do you notice that you can
blur and split your vision and see one object twice? Apparently, I was doing that a lot more than I realized. Maybe it's considered
double vision. I don't know.
So I practiced doing this, staring at a point in my ceiling and splitting my vision so that I saw it twice. When I brought the two images of the object back together, it was very difficult at first. It was like my brain was preventing my focus. But I kept trying. It became like a strange game -- bring the same object together until it becomes one image. I found that over time, my vision actually improved!
Not only that, I could bring things closer to my face without it getting as blurry. I also had better control over my vision. The headaches that would come about from improving my vision lessened over time. I may not have the best vision in the world, but I can see clearer than ever.
I don't know if any of this applies to you, but learning to control your focus by bringing your vision back together might help you to see better over time.
Good luck and Stay Safe!