Keen Eyein Pokémon Polished Crystal

Keen Eye is an ability that prevents the user's accuracy from being lowered by opposing Pokémon's moves or abilities. This means that moves like Sand Attack or abilities like Hustle will not affect a Pokémon with Keen Eye. It is found primarily on bird Pokémon such as Pidgey, Pidgeotto, and Pidgeot in Polished Crystal, however it does not only appear on flying type Pokémon! If your lead Pokémon has Keen Eye as its ability, the encounter rate for wild Pokémon is cut in half, IF the wild Pokémon is at least 5 levels lower.