Even on guitars I've had misfortunes. I never used to clip the strings on my guitar and then one day I accidentally poked my right eye with the E-string. My eye just wouldn't stop tearing up and I could barely keep it open. The doctor said I didn't do any major damage, but I had to wear a patch for a little while. I still have a tiny red mark on my eyeball from it; I'm still not sure it's the same.