Medusa50
I own Oakley
I have the same case. Many times the center of the O is popped out when they decommission the case. I made a few by using tracing paper and a pencil to shade the outline. Transfer that onto a sheet of black ABS plastic or lexan and cut out a new piece with a dremel. Sand the edges until it pops in and use a bit of caulk adhesive to secure it. Looks perfect.