  The comparative numerical and analytical analysis of scintillation indices of
the vortex Laguerre-Gaussian beam and the non-vortex doughnut hole and Gaussian
beams propagating in the randomly inhomogeneous atmosphere has been performed.
It has been found that the dependence of the scintillation index at the axis of
the optical vortex on the turbulence intensity at the path has the form of a
unit step. It has been shown that the behavior of scintillations in the cross
sections of vortex and non-vortex beams differs widely.
