Years ago when I was doing some welding work in the Navy, I scratched my cornea with a metal shaving when I was grinding some of the welds down as well as burned it, burn was dummy on my part as I forgot to lower my shield. Hurt like (censored) for a day or two, and had some real blurry vision out of my left eye for about a week or so. Doc had me wear a patch over my left eye and ordered me to wear my sunglasses at all times when awake for the following week after the patch came off. If I remember right, vision just slowly got back to "normal" after a while. Not to long I don't think. Every once in a while, if I look/concentrate just right, I can still see the scar in my eye.