In my experience of OP, OP often tells me when I am deficient in a mineral. For me it was zinc and calcium. Zinc is also a big factor in vision. You may be borderline deficient in that or another mineral which would explain the vision effect.
I do believe that the oil can trap minerals that the body uses, but I do not believe it produces problems unless a person is near or deficient in minerals. Being borderline deficient can produce long-term problems that will not show up for years, but will likely be more difficult to treat. With OP, we get a red flag earlier so we can fix it before it causes any real problems. With my minerals improved, I do not have the reactions.