Invest in breathable contacts that can be worn for multiple days. I don't normally wear contacts, but got tired of fussing with glasses on climbing trips. I went to my ophthalmologist and explained that I was looking for multi-day use contacts and he set me up with a pair that is apparently approved to keep in for up to 7 days. I don't really know how (or if) they are different from regular day-use contacts, but they have worked great for me. They require using special eye drops in the morning and evening to keep the lens clean and the eye lubricated, but keeping a little bottle of drops from freezing is not very hard. The only downside is that I get a lot of eye crud when I wake up in the morning, but have not had any other problems with them. Of course, I carry a spare case of glasses with me on all trips, just in case.
I don't remember the contact model off the top of my head, but can check when I get home.