Miracle Eye causes accuracy checks against the target to ignore changes to the target's evasion stat stages if its evasion stat stage is greater than 0. If Miracle Eye's target is a Dark-type Pokémon, it also removes the target's immunity to Psychic-type moves. Miracle Eye's effect ends when the target switches out.
It resets an enemy's evasiveness. Dark types can be hit by moves that would have no effect.* It resets an enemy's boosted evasiveness. If the enemy is Dark type, it also causes the Miracle Eye status condition, which allows Psychic-type moves to hit the enemy.*
In the anime
The user's eyes glow, allowing it to hit Dark-type Pokémon with Psychic-type moves.