I think the point is that the professor's stated philosophical beliefs (that sense-perceptions are an invalid means of knowing reality) contradict his commonsense desire for his daughter to have good vision, and thus his elaborate arguments are shown to be disconnected from reality.

The professor's hypocrisy isn't (non-negligible) evidence for or against the connectedness of his arguments to reality. Instead, it is evidence that there is divergence between the professor's stated beliefs and his actual beliefs (assuming he that he cares about his daughters eyesight, believes an optometrist can help her eyesight, etc...).