Ever seen "Drunken Master?"
Great, fun movie and it has a simlar concept. The hero has to get drunk (technicaly disabled in some fashion) in order to access his style of combat to its fullest. When he's sober, his fighting prowess is very limited.
While it is cool to think up funky fighting styles and classes to go with them, it is even better to give a reason why.
Blind fighting monk (thinking out loud)
Well, historicaly such monks learned marital arts to protect themselves and others in a land where only the noble could legally have weapons. So we can still use that.
But why blind? Did this particular brand of monk specialize in night time raids? Perhaps they learned how to ambush enemies in the dark of night? Or perhaps they belonged to a community that had a lot of mines and then the mines were infested with green skins. The monks learned how to fight the monsters in the dark. Perhaps they come from a land of no sun.
Now with some ideas to give some "logic" why monks fight "blind," we have come up with a couple of extra ideas to add to the mix and flavor.
The ambush monk could potentialy have the track ability, but it's only useable by touch. Meanwhile the mine monk could have some special close fighting techniques or avoid some reach weapons (spear) that were used by the orcs in their mining raids.
We also have to remember that the original concept behind the PrCs was not to just give players access to cool, funky abilites, but to offer a unique class that reflected something from the GM's unique world.