The Omega Effect is a strange force of entropy, perhaps a destructive side to the often creative nature of the Source.
It is Darkseid's possession of the Omega Effect that allows him to fire his Omega Beams from his eyes. These beams are capable of vaporizing, erasing, as energy blasts/energy beams or transmuting any form of matter, living or non-living. They can send/retrieve something from different places, times, dimensions, and even universes.
Darkseid uses his Omega Beam to send Batman back in time at the climax of Final Crisis. From there Batman had to journey through time in order to get back home to his own time period.
It is practically impossible to avoid, dodge or deflect Darkseid's Omega Beams, as the beams are able to make sharp turns around obstacles and few can withstand a direct hit from them.
Two of Darkseid's children, Grayven and Grail inherited a portion of the Omega Effect
In Other Media
Justice League Unlimited
As Darkseid comments in the Justice League Unlimited TV series, Batman is the first and only human to dodge his Omega Beams (seen in the final season).