In reply to AndrewB121:
I use 30 dayers. To be clear, they need to be removed every night.
The issue for mountaineering with contacts is cleanliness. Water can be at a premium in rifugios.
Always wash hands carefully and thoroughly before touching your eyes or the lenses. Infections can wreck holidays at the very least.
On the mountains at least use the best protein removing solutions.
Carry a small mirror (like those for applying makeup). Rifugios are also usually dark.
Carry at least one set of spares and eye drops. Dry eyes make the lenses sticky and prone to 'rolling'.
Also 2 or 3 Qtips just in case one rolls under your eye lid. If this happens, it's not a disaster, take your time with a head torch and the mirror.
The altitude, high UV, dessicated air and physical stress (all of which is part of the reason for being there), can take its toll.
At home get into good habits and never, no matter how tired you are, sleep with them in.
I've used them for 15 years and wouldn't want anything else.
Good luck.