The Smudge on the Rearview Mirror

Dear Delyara, I went to adjust the mirror in my car before backing out of the driveway this morning, and my thumb slipped, leaving a thick, oily smudge right across the center of the glass. During my entire drive, every time I checked behind me, the headlights of the cars trailing me blurred into a long, distorted streak of light that made it impossible to judge the distance. I didn't have a cloth in the glovebox to clean it. I just had to drive through the dark with a distorted view of what was coming up behind me, my eyes straining against the smear.