That sucks, and certainly not a circumstance one would prepare for. Have tried monocular vision (aka one contact for distance) but found depth perception to be compromised and hence confidence.
My first experience of a similar nature, losing a contact, was at the 1980 Champs, second day, about 10 minutes before the finish. Quite disconcerting, cost me a little time but not enough to explain the couple of minutes that I ended up behind winner Eric Weyman. But it did let me find out what Jim Pugh used to do, train O' from time to time with just one contact, because you never know. Would have been useful to have done that.
These days I run with just one contact, so lots of things are blurry. And it gets interesting if I lose it, since then my distance vision is gone. Did that at the NA Champs a few years back at Cleveland, lost the contact early in the course. The initial reaction was I'm fucked, but then it was just a matter of doing some very focused and precise orienteering. Which turned out to be possible even if I couldn't see very far. Quite a surprising experience, though I really don't care to repeat it.
I recall reading of your Cleveland experience...more mental focus than I'm capable of! Time for a small-of-the-back pack with a pair of extra glasses & a compass for important meets (eg, champs such as this or meets one flies to) at least.