After 20 minutes of using Apple's new MacBook Pro with Retina Display, I switched back to my own six-month-old MacBook Pro to send an email. But when I looked at its screen, I thought my contact lenses had actually fallen out. For a second I was worried; everything on the screen looked less crisp and less bright. It's not an old machine, but it was really as if an optometrist had switched my prescription, or I'd been forced to use my old glasses. Everything just seemed blurry by comparison.