Put a screen protector on it.
I have some small scratches on my iPad mini. You can only see them in certain lighting but it bugged me. I don't know how they got there. I was very careful with it. I had it in a smart case which protects both the screen and back and I kept that inside a zipped pouch when in my bag for extra protection. Anyway after a few weeks I noticed these very fine scratches on the screen, when viewed at certain angles under certain lights. I quickly put a screen protector on there to prevent it from getting anymore scratches. Now I can't see any of the scratches anymore. It's just a regular screen protector. Not a matte one.