Lens of Truth

The Lens of Truth is an artifact that lets Link see "the truth" and is found in Ocarina of Time and Majora's Mask. Link first hears about the item when an old man in Kakariko tells him about a man who could see the truth and whose house stood where the well is now. The Lens of Truth allows the user to see things that are not normally visible to the naked eye. It shows which walls, floors, and objects are fake, and it allows the user to see things such as invisible ladders, platforms, enemies, and ghosts. Be warned, as it drains Magic Power over time (although if you set the lens to a button, then tap the button repeatedly and it will not drain your magic).

The Lens of Truth is also referred to as the Eye of Truth and looks very similar to the Sheikah's eye symbol, with the handle as the tear.

In Ocarina of Time, the Lens of Truth can be found in the Bottom of the Well. In Majora's Mask, it can be found in a cave in the Goron Village near Snowhead.

In Twilight Princess, Wolf Link's finely-tuned wolf senses perform a function similar to that of the Lens of Truth.

Trivia

 * In Ocarina of Time, if you play Song of Storms and then use the Lens of Truth it will NOT drain magic energy.