This one comes from the streets and some of these signs are correct but most of them are not. I have seen several versions of this and all of them are incorrect.
The sign is obviously warning people that there is someone in the area that is blind and to be more careful I guess. According to my friend it says "warning! blind person" or something like that but the funnier part about this sign is it's placement. You don't even need to have impaired vision to accidentally miss this sign since it is hiding around the corner. Maybe the blind person is exceptionally dangerous? Plus, what sort of level of activity is actually going to take place down this tiny side street?