  In recent photodoping experiments Decca et al. [PRL 85, 3708 (2000)] have
observed an unusually long-ranged proximity effect between the superconducting
and insulating phases of YBCO. Here we critically examine the claim in that
reference that such long range is anomalous. We show that, once the novel
nature of the experiments has been properly accounted for, the conventional
theory of the proximity effect predicts comparably long ranges.
