I frequent the Drawings, Prints and photographs wing at Metropolitan Museum of Art, here in NYC. There is a long passage where the work is hung mostly in a horizontal line. I've noticed they are just slightly above my eye level. I'm short, about 5'6". So maybe if I were about 5'8" - 5'9" they'd be eye level. But anything goes, and let's face it, wives always right, even when they're dead wrong.