Well I think it's mainly my eye sight.  It's weird because it seemed to be different before, it's strange that I only noticed it last week.  
Anyway I booked in to the genius bar and the guy there said he could see a bit of flickering.  The result?  Brand new display fitted.  Gotta love the customer service!  Still looks pretty much the same, so I'm gonna have to finally get me some glasses I think lol.