Surely that argument is refuted by the fact that the newly sighted do not receive the same qualia as the always-sighted?

Yes, it is, when you accept the evidence you've given as valid and can weight arguments based on their probability logic. Denial mechanisms in place will usually prevent proponents of the argument from recognizing the refutation as a valid one. Lots of difficult argumentation and untangling of webs of rationalizations ensues (and arguing by the Occam's Razor route is even less practical, because in their model, their hypotheses of soul or outer-light or what-have-you is simpler when other parts of their model of the whole world are taken into account, which means even more knots to untangle).

I seek to circumvent that debate entirely by putting the burden of proof on my own "side", for several reasons, some of which are tinted a slight shade of gray closer to the Dark Arts than I would like.