The three gigantic one eyed workmen of Vulcan who made Jupiter's thunderbolts were the  Cyclopes 

They were, Arges (ar-jez) with his stream of light, Brontes with his thunder, and Steropes with his lightning.

Orion, blind and helpless, once wandered to their cave, when one of the Cyclopes took pity on him, and led him to the sun, and thus restored his sight.

These Cyclopes (or Cyclops) had only one eye, and this was in the center of the foreliead.

They were the sons of  Uranus and Gaia.

(si-clo'pez). [also Cyclops]