Dark Eyes were presumably robotic hovering robot orb that act as enemy mobs in Dragonball online. They ared with a single laser.
The name Dark Eyes was mistaken for the name of the Time-travelling villain group that were known as the Time Breakers.
The Dark Eye is an evil organization that has divided the earth into several pieces. The Dark Eye appears to be the main threat of Dragon Ball Online on release. It is possible that Trunks is attempting to save the earth from the Dark Eye by time traveling and warning people much like he did in the anime to save earth from the Androids.