How could a person survive one of your adventures if they wear glasses, or contacts, and lose them? What about seeing underwater while wearing contacts?

Well, I wear both. You just deal with it. I'm sure that you would get your bearings by using other senses as well. I sometimes judge distances by the shadows that are cast. I have really bad eyesight - 6.5 in the left eye and 7.0 in the right when wearing contacts.

You can see underwater with contacts for short periods of time. Just use your memory banks when taking the second dive.