Transparent Material not showing in viewport on linked object

Hi folks, not sure if this is the correct section to post this, so apologies if not. I’m working in 2.79b and wondering if someone has an idea about this, or whether it’s maybe a bug. I’ve created a rigged character, and now have him linked into a new file. I’ve set the lens of his eyes to show as transparent in the original file,
Original File

but when I link him into the new file, they show as being opaque again. Makes it a bit tricky to see where he’s looking. Am I missing a button somewhere in the new file for the viewport or is this just something that doesn’t transport over with a linked file.
Linked file

Thanks in advance!