Lens

Lenses are an uncommon drop from Demon Eyes.

Another form of lens, called the Black Lens, can be used to craft Sunglasses. Black Lenses have a much lower drop rate than the standard Lenses.

Making money
A much better way to get money from lens, is to craft a Suspicious Looking Eye, killing the Eye of Cthulhu and selling the reward.

History
Lentille