My Zennis have lasted nearly a year, despite a protracted attempt by a toddler to yank them off my face, throw them across the room, or otherwise destroy them.

Even if they did fall apart after six months, it's more affordable to replace them than to buy new Ralph Lauren or whatever frames for $300 apiece.

(How about not letting your toddler run amok all over your face, Dad-of-the-Year? naysayers might criticize. And they might be right, but you can't win every battle.)