Blurry icons on Retina MacBook Pro

Hey, all.

So a few apps on my RMBP are "blurry" and fuzzy", even less clear than my iMac (non-retina). (See Screenshot below). I don't belive it is the developer's issue. Especially as iBooks Author (one of the problem apps) is made by Apple...

Any reason for this?

K5yw0j5_medium

via i.imgur.com

Cheers!