Lens

A Lens is a common crafting material that has a chance to drop from Demon Eyes and Wandering Eyes.

Tips

 * A much better way to get money from lenses, rather than simply selling them, is to accumulate them to craft Suspicious Looking Eyes, kill the Eye of Cthulhu, and sell the rewards.
 * Later in the game, Mechanical Eyes can be crafted and used similarly, but even in the advanced game, The Twins remain a tougher opponent, and profiting off their drops is a rather more involved process.

Trivia

 * In some of his quotes, the Merchant claims to sell lenses, despite not actually selling them.