I did 25 miles today. My legs maybe could've handled more, but my back was screaming at about mile 21. Plus the last 5 or so were into a crazy headwind. I somehow managed to blink my contact out of my eye about 2 miles from the end - it adhered to my sunglasses (thank goodness) but then I had to figure out how to get it back in my eye with the crazy wind. Without the contact I wouldn't have been able to drive home!