Observed magnitudes of many quasars with redshifts exceeding z = 5 correspond to luminosities Lbol > 1014 L⊙. The
standard mechanism of quasar energy release by accretion suggests that masses of superluminous quasars should exceed
1010 M⊙. On the other hand, the age of these objects in the standard cosmological model is below one billion years, which
is too short to explain their formation in the early Universe. Many quasars are known to be gravitationally lensed; showing
multiple images of the same object. In the case of remote quasars with no multiple images, it is still possible that they are
also gravitationally lensed by foreground objects of intermediate masses, such as globular clusters or dwarf galaxies. Such
mesolensing would result in essential amplification of quasar brightnesses, subject to geometrical configuration between
the lens and the lensed object. Here we estimate the fraction of quasars whose brightness might have been amplified by
gravitational lensing.