i literally can't imagine this happening to me-- I'm so blind that at my last eye exam, I jokingly put my hand about six inches from my face and told the optometrist "this is about my maximum viewing distance!" and he moved my palm closer to my face by another three inches and said, "Actually, this is more like it." I have to get the highest index possible or i get mad distortion from the thickness of the lenses, and i just can't afford them these days, so I wear contacts now-- but I wore glasses until I was about 22 and I still remember the visceral panic of not being able to see anything! it's a complete and sudden loss of control. It's actually one of the reasons i switched to contacts, so I wouldn't have to be in that situation again where my glasses got lost or broken and I couldn't see anything. I had school officials break them twice when I was a kid (by accident), and that was enough exposure to navigating the world blindly to make me never want to experience it again.