The Golden Eye is a tool from the OpenBlocks mod. This tool is used to find any naturally generated structure. It has 100 durability, and can be recharged by combining it with Ender Pearls in a Crafting Table. It takes roughly 9 Ender Pearls to fully recharge a Golden Eye from a completely uncharged state.
This creates a completely uncharged Golden Eye; it will need to be charged with Ender Pearls.
Sneak+right click while holding the tool, then right click and it will shoot off several blocks into the distance, like an Eye of Ender finding a Stronghold. From this point it can be used exactly the same as an Eye of Ender is used.