How do you get a mechanical eye in Terraria?

[redkoala489]

The Mechanical Eye can be obtained by killing Hardmode enemies.

[goldenkoala386]

Lenses are crafting materials which can only be obtained as drops from Demon Eyes and Wandering Eyes.

Similarly, what does Plantera drop? Plantera is a Hardmode boss that can be fought in the Underground Jungle after all three Mechanical Bosses (The Destroyer, Skeletron Prime, and The Twins) have been defeated. Plantera drops a Temple Key upon defeat, allowing access to the Jungle Temple.

Also asked, how do you summon the twin eyes in Terraria?

The Twins can be summoned manually using a Mechanical Eye at night (7:30 PM to 4:30 AM).

How long is a Terraria day?

One minute of in-game time lasts one second of real-world time, meaning one hour in-game lasts one minute real-world. One Terraria day, therefore, lasts 15 real-world minutes, and night lasts 9 real-world minutes.