Lens of Truth

The Lens of Truth alows Link to see invisible objects in the game. It shows things like ghosts and a ladder. but at the expense of majic, so a tip dont use it alot or nonstop.

Ocarina of Time

The Lens of Truth is found in the Bottom of the Well.

Majoras Mask

The item is found in the Goron Shrine. It allows the user to see the "truth" at the expense of magic.