Blind Fight

In melee, every time you miss because of concealment, you can reroll your miss chance percentile roll one time to see if you actually hit. An invisible attacker gets no advantages related to hitting you in melee. That is, you don't lose your Dexterity bonus to Armor Class, and the attacker doesn't get the usual +2 bonus for being invisible. The invisible attacker's bonuses do still apply for ranged attacks, however. You also gain immunity to gaze attacks.