"In Front of Me"
As someone once corrected me regarding flanking, there is no facing in 3e. No facing means there is no "in front of me."
Consequently, you couldn't assume to know where something (even an area) was if you couldn't see it.
There can also be no valid assertion that a character was looking at a particular location at a precise moment during combat. Hell, a monk can deflect arrows from 360 -- would/can he argue he was looking in a different direction at the time? Nonsense.
So let's say the DM bought into the facing argument....if you are suddenly struck blind -- who's to say you didn't change your facing? It's not something that is communicated because D&D combat assumes players are constantly scanning the battlefield in all directions. That's how they get around the facing issue in the first place.
That said, the rules do not really allow aiming success by default just because a player insists he was looking in a particular direction when struck blind "I swear! I was lookin' right THERE a second ago!" Who knows where the wizard is lookin? He'd argue the 360-awareness thing if it would protect him from a deadly blow.
I'd require a concentration check just for the directional aspect. A failure should yield a random location by die roll. No?
wolfen