Safari has stopped loading images

Ok so I seriously need some help quickly here, I've been on my laptop all day and it's been fine but since about an hour ago (although I didn't know the extent of it until just now after trying a few different webpages) Safari has just stopped loading any images whatsoever. I thought it may have just been a Youtube glitch, where I first saw it, when the thumbnails weren't loading but the videos were working fine but now I've noticed that no webpage is loading any images at all, no logos, no photos, no buttons in some cases which must be clickable images I guess. I've tried the good old 'quit and reopen it and hope it's fixed itself' method and tried restarting my entire Macbook (a mid-2011 Macbook Air if it makes any difference) but neither has fixed it. Has something been disabled/enabled somehow that I'm not aware of or what?

To note too I also updated Safari yesterday to 6.1.5, along with iTunes and some security settings too I think when the system update popped up if that may have effected it somehow although it's been working fine all day up until now. I seriously need some help asap!