I only know of one time that I've been in complete darkness. On the tour through Onondaga Cave in Missouri. About half way through the tour, the guide turned off all the lights in the cave and then said to the tourists, "You know how, when you're in the dark, if you wait a while your eyes will soon start to get accustomed to it and see a little. That won't happen here ... no matter how long you wait."
This post was edited by Benedict Arnold at December 13, 2017 2:50 AM MST