That's fascinating, and somewhat similar to my own experience. I was born with a large, central vision-obscuring cataract (or developed it very early on) in my left eye, and my optometrist told my parents not to worry about it, so they didn't.
My left vision was as you described, very low-resolution and dark, with the addition of a large dark spot near the middle. I read with my right eye, though it felt like a little bit of the left was integrated. This led to eye strain, especially after I got into software and spent 8-10 hours a day staring at tiny text on a screen.
I had the lens with the cataract removed at 26, and while it was initially fascinating to have brighter vision and be able to make out large print words, I eventually felt kind of disappointed that I didn't have a better result. My vision was still very blurry (significantly worse than the right eye), and since the artificial lens I received can't flex to focus like a real lens, glasses only correct for a single fixed distance, and text had a weird shimmer to it that made it very difficult to read when my brain integrated the two images. So I mostly stopped wearing glasses and went back to reading with my right eye.
But I recently had a series of headaches due to eyestrain, got a new reading prescription that was better than the old one, and have been wearing glasses any time I read or look at a monitor. And until you mentioned it, I hadn't really realized that the "shimmer" is almost gone, and my left vision is much better than at any other point in my life. Cool!