I can remember this happening with my grandparents .... their eyes were covered with pennies. I remember my mum handing me the pennies and holding me up to place them on the body. I was frightened, and mum told me, "Don't be scared of the dead - they can't hurt you. It's the living you need to be scared of".
By the time mum died things must've changed, as I don't recall this being an option. Mum spent her last night on earth in the church she'd always worshipped at, when she was alive.