If blind folded, I would probably experience tripping over and, hence, pain, dizziness and death. I was thinking more metaphysically. However, this is interesting. Not too sure how practising techniques blinded would go
I have been in more than one dojo where practising very slowly with eyes closed, including being surrounded by others and needing to blend and move out of the circle, was practised from time to time. And I often do kokyudosa with eyes closed. All very valuable.