Dark Wikipedia and contact lenses

So I noticed something interesting today. If you're using Mozilla Firefox (Version 3 was just released and is highly recommended for use as your standard browser), you might know about the extension Greasemonkey. It allows you to install various "user scripts" (one of the biggest repositories being Userscripts.org) that change the layout of many websites. Some add features, some remove others, and even others change the entire color palette of a website. Being a dark skin fanatic, I had to have one for both Wikipedia and Google (there are several for both). Anyway, SKYY's version of Dark Wikipedia is an excellent script, and is the one I use. Incidentially, the links on Wikipedia are blue. Now you're probably wondering where the "contact lenses" part of the title comes from, and I'm about to tell you. If you happen to be wearing a pair, the blue links on the dark background surrounded by the white text makes a strange popping out effect, as if your screen is 3D. It's actually quite cool, but knowing very little of the human eye (I slept during most of my biology class, but my teacher sucked anyway), I don't have an idea as to why this occurs. Probably related to optical illusions and those polarized red-and-blue 3D glasses. Anyway, if anyone has contact lenses and Firefox, check this neat little trick out.