  It has been suggested that the fuzzy nature of spacetime at the Planck scale
may cause lightwaves to lose phase coherence, and if severe enough this could
blur images of distant point-like sources sufficiently that they do not form an
Airy pattern at the focal plane of a telescope. Blurring this dramatic has
already been observationally ruled out by images from Hubble Space Telescope
(HST), but I show that the underlying phenomenon could still be stronger than
previously considered. It is harder to detect, which may explain why it has
gone unseen. A systematic search is made in archival HST images of among the
highest known redshift quasars. Planck-scale induced blurring may be evident,
but this could be confused with partially resolved sources.
