Compound Eyes is an ability introduced in Generation III. So far, 1 Pokémon has this ability.
Compound Eyes raises the accuracy of a move by 30% in battles.
Outside of battle
If a Pokémon with Compound Eyes leads the party, even if it has fainted, the chance of finding a Pokémon in the wild holding an item increases from 50%/5%/1% to 60%/20%/5%.
Pokémon with Compound Eyes