Is there such thing as blind people being able, at least to a certain extent, to sense objects around them? I don’t know where I read it, but I know I’ve heard it somewhere. I know there’s been studies done of people (not necessarily blind) being able to sense others staring at them. I don’t know if that same sort of sense applies to the blind.
This is kind of a GQ, but I will shoot.
The brain is efficient with space. In blind people, regions of the optic cortex are given to other areas. Regions dealing with aural and tactile processing increase, and it is safe to assume that blind people have greater acuity at touching, hearing, or smelling than the sighted.
That being said, a greater perception of touch or hearing can give one spatial sensation without sight, namely hearing echoes and perceiving close objects by feelings on the face. If you walk down the hall with your eyes closed, even the sighted can tell if they are about to run into a wall.
I don’t know how sensitive it is, but Bank of America is running a commercial with a blind woman performing martial arts. No idea if this is real or not, but you wouldn’t think that that woman would have to use a cane (which she unfolds at the end of the commercial).
A very good friend of mine has been blind since childhood. She has a very high level of spatial awareness. She says that she knows the basic layout of my room based on the way sound echoes, but needs to touch all the furniture if I want to discuss how I’ve arranged things. She has told me, however, that most people who are blind from birth can not do this, as there is little, if anything, to relate these things to (she mumbled something about needing a “sighted perception” to understand the shape of objects). So far as a greater acuity of other senses, she’s told me that to her, it’s more a matter of paying more attention to those things rather than being inherently better at them. YMMV. She usually knows when I’m looking at her because she can hear the movements I’m making, and which way my head is turned if I’m making any sort of noise with my head (sighing, talking, loud breathing, playing with my tongue ring, etc).
I’m working on teaching her fencing. So far, we need to figure out how to give her an awareness of where her opponent’s foil is, and we’ll be ready to go. She says that martial arts are pretty feasible/possible so long as the opponent is making noise of some sort, or you know where the target is.
If you’d like further info, I’m more than happy to ask her these things… the above are all things that have come up in conversation before. Just let me know. 
And I believe this should be in GQ. I’ll let a mod know.
I saw a blind guy on TV once who could navigate by sonar - he made clicking noises with his mouth and could tell where stuff was by the echo. They demonstrated this by walking down a street with him, he would point out where there were poles and such. Of course, he was a rare enough exception to have a portion of a TV program devoted to this ability.