Tinted Lens is an ability introduced in Generation 4. So far, 2 Pokémon have this ability.
Tinted Lens doubles the power of any moves that the Pokémon uses that are not very effective against its targets. If a move is regularly not very effective, and thus normally does half damage, it would therefore do normal damage, while a doubly resisted move will do half damage rather than 1/4 damage.
Outside of battle
Tinted Lens has no effect outside of battle.
Pokémon with Tinted Lens