You're right, I forgot my ready action was only a partial round. All I did was walk over too him, I'd say that's only slightly generous.

I was unaware that I didn't get to know the duration of my own spell. I always thought that it would indicate if that was an unknown, as with dust of disappearance.
Quote Originally Posted by SRD
The greater invisibility bestowed by the dust lasts for 2d6 rounds.The invisible creature doesn’t know when the duration will end.
I rolled attacks for the max possible blind rounds I would get, to save on multiple postings. In any event, is it not obvious to my character when someone goes from blinded to not blinded (reacting to attacks better, not sightlessly blinking and staring into space...)?