Dear random person who found my blog by searching for "Does David Tennant wear glasses?":

Yes. You can see him in them in segments of Doctor Who Confidential where they've given him a camera to babble at in his dressing room before he gets into costume for shooting. Before he goes into makeup, at ass o'clock in the morning when he's still clinging to his coffee like a lifeline, he wears specs. Since he's wearing them even when not doing any close picky work, I would assume he is nearsighted. During shooting he either wears contacts or just goes about sort of blind-ish. I can't tell if he's using his own spectacles as 10Doc's "brainy glasses", but the frames are similar at the least.

Hope that helps. :)