Blinding Shield was a new paladin ability that would come with Cataclysm, learned at level 81. It was first announced in the Cataclysm paladin preview. However it seems to have been removed and replaced with Inquisition as the level 81 ability.

Blinding Shield would damage and blind all nearby targets. This effect might have ended up only damaging those facing the paladin's shield, in a manner similar to Eadric the Pure's ability Radiance in Trial of the Champion. The Holy tree would have a talent to increase the damage and critical strike chance, while the Protection tree would have a talent to make this spell instant cast. 2-second base cast time. Requires a shield.