Prolific Youtuber XboyAhoy has put together a series of videos on Black Ops 2 to focus upon the weapon attachments available in the game, and to discuss their unique properties.
In his latest episode, XboyAhoy talks about the EOTech sight attachment, which serves as the mid-range alternative to the Reflex sight available to most weapons. He explains that the EOTech is modeled after the real life EOTech 500 Series of holographic sights for their use of laser diodes that cast an illuminated hologram at the reticle onto an optical window.
In-game, the EOTech is available for assault rifles, SMGs and LMGs, but it isn't available to the shotguns, crossbow, or handguns. He's discovered that the EOTech sight provides a 1% centerspeed improvement to your aim.
He goes on to further explain what you can unlock with EOTech sight by using it in game, which include additional reticles.
The video's well worth the watch if you play Black Ops 2 and wish to learn more about the stuff you put on your guns.