At the heart of every Eye is an Icarus Core. It is an ancient drive system that survived the undoing of Creation in ages past; the Lost Ages. High technology lost to the current age, Icarus Cores cannot be reproduced.
In the Dawn Era, seven of these devices were found in the flotsam of the Sea of Entropy. Recovered by the Third Instructor, also of a different age, they were put to use in support of the Nawirrûs Covenant. They were used as a source of power for the The Eyes, giving them rapid mobility in the Astral Sea and an artificial environment.
Without protective measures, Icarus Cores are extremely dangerous. The Third Instructor, pragmatic to the extreme, saw a greater good for using them over the slight chance of a catastrophic explosion. After the loss of The Second Eye and an entire world, the Third Instructor reconsidered their use. He realized that the Icarus Cores were too dangerous without safety measures; the stuff to keep the Icarus Core form triggering a chain reaction, destroying itself and everything around it. Such measures were common when they were built, now nothing existed. Near the end of the Dawn Era, all of The Eyes and their dangerous engines were hidden away in the Astral Sea.