Smudged sunglasses

My 15 month old is obsessed with my sunglasses. He loves to take them off my face, attempt to put them on his, but generally he just loves to put them in his mouth! The moment we get in the car & he notices I'm wearing them his hands are instantly in the "gimme, gimme, gimme" position. I give in every time.  You think by now I'd carry an additional pair, but he would just want those too. When I go to put them on later in the day, when he's not around of course, it's almost impossible to see out of them. To most, this would drive you crazy. To me, it's a reminder that one day soon, he will not want to play with my sunglasses, and the smudges will be gone. So, for now, I am going to cherish every smudge for as long as I can.