One of its new MacBook Pro models has a "Retina" display, a screen that packs four times as many pixels as a standard display. Why is this a big deal? It's not easy to describe in print, but a look at the screen tells the whole story. It's like putting on glasses and realizing you're nearsighted. Much like the screen on the latest iPad, the new display makes all other screens look dull and fuzzy. Even the icons on the Mac screen look so much more detailed. On the calendar icon, you can make out the dots for the individual dates. On the Address book, you suddenly see that the "at" sign on the cover is embossed. High-resolution photos look really, really sharp. Low-resolution photos, like those on Facebook, are revealed as mushy and indistinct. With a resolution of 2,880 by 1,800 pixels, the Retina screen can show every pixel in a five-megapixel shot, all at once. It has more pixels than a high-definition TV set - 2.5 times as many.