I think websurfing is a hunting activity. The eye is looking for anamolies, for things that don’t belong. (That might be why the word anomaly, spelled wrong in the previous sentence, got your focus).
Once our peripheral vision confirms that something is familiar, we can ignore it and just worry about the new stuff. Squidoo is stuffed with new stuff (nearly all our visitors are first-time visitors) and so, for example, there’s almost no focus on our Google AdWords. That’s because they’re familiar.