I actually finally got glasses for the first time since 16 years of age, because I was worried that my luck would run out one day on the playa--but my luck (as a soft lense disposable wearer) continues to hold. I bring the specs every time, just in case.
I bring spare a lot of spare contacts and solution (one big bottle and a couple of little ones--they'll get used up if I don't crack them open or give them away as gifts.) Also, a spare lense case and few tiny bottles of artificial tears and (separately) redness reliever, because if you use redness reliever when you only need tears, your eyes allegedly get dependent on it. Heh.
I hate how my eyes feel when I sleep with them in, so I wash my hands and remove the lenses every night. If you can't wash your hands to your satisfaction, might be better to sleep with them in, though, and handle it the next day.
I never had any trouble out there but my campmate did, and had to wear her glasses for a few days.