How to know if oleophobic coating is still on?

Hello! I have seen a few scratches on my iPod touch 5's screen (they are only visible when a bright light is pointed on the screen) and I thought there was no way to fix it. Until (after researching for four days) I descovered what an oleophobic is...how will I know if it is still on?

They say that when you see scratches on the screen it's really not the screen but the oleophobic, so I'm wondering if the oleophobic is still on the screen and if it gets removed will the scratches also be gone?

But first I need to know if the oleophobic thing is still on....how will I know? Thanks! 🙂