From what we've seen, there appears to be plenty of space on the screen to show incoming calls, read emails with eight lines of text at a time, viewappointment details, select songs and control volume, and, of course, see the current time.
Customers must make an appointment in order to view frames, since the area is small, but that worked to my advantage: A friendly salesgirl met me at the elevator when I arrived and tended to me quite cleverly while I tried on several pairs.