The Optic Staff is a Hardmodesummon weapon that summons a miniature version of The Twins in their second form, which follow the player and attack enemies. The summoned pair of minions, named Spazmamini and Retinamini, deal damage with a ramming attack and ranged laser attack, respectively. Like other minions, the summoned Twins is invincible and follows the player for an unlimited amount of time, unless the player dies, summons a replacement minion, cancels the buff, or leaves the world.
Its best modifier is Ruthless. The Mythical modifier provides the widest array of stat bonuses, but these primarily affect the initial summon rather than the resulting minion. Additionally, minions cannot deal critical hits. The only lasting advantage a Mythical Optic Staff has over a Ruthless one is knockback.
One pair of Twins counts as one minion toward the maximum minion count.
Therefore, a player can get 22 "minions" with maximum minion capacity, as opposed to the usual 11 full sized minions or 14 spiders.
Retinamini's laser projectiles travel straight forward, so they may miss against fast or far away enemies. They also emit a small amount of light.
Due to their piercing attacks, the Twins can only hit the same enemy a maximum of 6 times per second, regardless of how many Twins are summoned (this applies to all weapons and summons that pierce enemies except the Razorblade Typhoon at 10 hits/s).
It is possible to get non matching amounts of Retinaminis and Spazmaminis by maxing the spawn cap and lowering it. Prior to 1.4, It was also possible to get an odd amount by summoning spiders with the Spider Staff after summoning the Twins, since the spiders only would count as 0.75 of a minion.
Unlike most flying minions, the Twins will not naturally pass through blocks unless the player has moved out of range. This makes them very prone to getting stuck in tight areas and caves.
The Optic Staff is effective against bosses, as each Twin attacks individually. It is especially effective against The Destroyer, as the Spazmamini will pierce each segment.
The icon indicating that game data is saving on the Nintendo 3DS version resembles the Optic Staff minions, except it resembles more the first stage of a Retinazer, instead of the second, mechanized stage.
Unlike the Twins boss, the minions are not connected by a tendril. Furthermore, Spazmamini does not spew Cursed Flames like Spazmatism does.
There is an occurrence when using the Optic Staff where only one or two Retinamini will remain with the player, while one Spazmamini (or vice versa) will be left behind due to obstacles. This bug is more likely to happen when the player is crossing some obstacles that the minions cannot. This can be fixed by removing the minions and spawning them again.