well, idk what's in the food around you, but just that i know for sure this was the root of it for me.

i think probably eating fish helps vision, probably also liver, but in both cases obviously try to get the cleanest source you can. they feed everything with corn these days in europe and that is an allergen for me, the smell of it in the meats makes me sick. even the eggs, i can smell the corn in it. i have to somewhat overcook corn fed meat to tolerate it.