Mechanical Eye

Type	Boss summonCrafting material
Consumable	✔️
Use time	45 (Very slow)
Tooltip	Summons The Twins
Rarity
Research	3 required
Use	https://terraria.wiki.gg/wiki/File:Roar_0.wav

The Mechanical Eye is a Hardmode boss-summoning item used to summon The Twins, the Hardmode version of the Eye of Cthulhu. It can only be used at night; attempting to use this item during the day will not spawn the Twins nor consume the item. The Mechanical Eye is also unusable while the Twins are already alive. If the Twins have not been defeated yet in a Hardmode world, all enemies have a 1/2500 (0.04%) chance of dropping a Mechanical Eye, with the exception of statue-spawned enemies, Meteor Heads, and Old One's Army enemies.

Crafting

Recipes

Result	Ingredients	Crafting station
Mechanical Eye	Lens3 Any Iron Bar5 Soul of Light6	Mythril Anvil or Orichalcum Anvil

Used in

Result	Ingredients	Crafting station
Ocram's Razor(Desktop, Console and Mobile versions)	Mechanical Eye Mechanical Skull Mechanical Worm	Mythril Anvil or Orichalcum Anvil
Suspicious Looking Skull(Old-gen console and 3DS versions)	Mechanical Skull Mechanical Eye2 Adamantite Bar or Titanium Bar10 Soul of Night5 Soul of Light5	Mythril Anvil or Orichalcum Anvil

Notes

(Desktop, Console and Mobile versions) In the get fixed boi secret world seed, the Mechanical Eye is not consumable and is instead a crafting material for the Ocram's Razor, an item used to summon Mechdusa.
Like other mechanical boss-summoning items, the Mechanical Eye can be brought to pre-Hardmode worlds and will successfully summon The Twins there.
As with several items, the Mechanical Eye has multiple crafting recipes (two in total) due to some items in the recipe allowing substitutes.