I really dont like this idea simply because infravision is not a cure for blindness.
It would not cure blindness, but it would lower the affects of dirt kick, it wouldn't lower ac and hitroll as much as normal, but the dirted person could not specifically target someone.
You see the outline of a small/medium/large person here.
They couldn't use flame arrow or path of deceit, but they could throw out an area spell and hope it's the person they were fighting.
eidted...