On a relatively quiet dance floor, I have sometimes closed my eyes for a bar or two, particularly while circling in one area. As long as nobody is carving up the floor, it is completely safe, and allows me to be truly aware of my partner's disposition. It is a wonderful thing to do, but of necessity one must have a quick look around to update the sense of where you are on the floor and where everyone else has got to.
On a related note, a delightful teacher from Holland made me do an exercise thusly:
She made me lead her "forgetting entirely about myself, concentrating on what steps I would like her to take", imagining that she were dancing alone on the floor. Of necessity I had to do this with my eyes closed, as the visual distrations took away my focus. She then back-led me to prevent me from leading her into trouble.
It was a very interesting and free experience and helped me choreograph much easier and more coherent steps for her to dance. I think everyone should try dancing a few steps blind, (like, say 3 or 4) just to see what it's like, but a word of warning - our balance is controlled by our inner ear, but vision provides much more rapid and fine adjustments. Our balance is less good without sight, and we have not had the practice of permanently blind people.
