The player's right eye will be replaced by a mechanical eye that shoots a continuous laser.
Fires a continuous laser as you shoot tears. The laser pierces enemies. Lowers current tear rate.
As any character, except Cain, tears will still fire from your left eye as before Technology 2 was acquired. Cain, not having a left eye, will only fire the laser.
Multiplies damage by .65
Beware: During the boss fight with Isaac or ???, it will provoke retaliation for each damage tick done to it. With Technology 2 this can amount to approximately 10-15 shots per second in your general direction.
Some special shot effects (e.g. Ouija Board) do not apply to the laser.
Ipecac: Stacks if acquired before Technology 2.
Mom's Knife: Warning. Will cause the beam to still shoot, but will no longer do damage.
Bob's Rotten Head: Warning. Will not be thrown when used with this, and the laser stops showing up but still does damage in the standard way. Isaac will be frozen in the primed position with Bob's Rotten Head. Position and laser can be returned back by pressing Space again.
Brimstone: Stacks. A persistent laser will fire while you charge Brimstone's laser. With this combo, Cain will only fire Technology 2. Note that this works oddly when Technology 2 is acquired first, but it still functions. If Technology 2 is acquired first, Brimstone will not give its usual great damage buff, making the Brimstone beam very weak.
Dr. Fetus / Epic Fetus: Stacks if acquired before these items. A laser will shoot out of your right eye and bombs will replace tears and come out of your left eye. (May decrease rate of fire.) NOTE: If Technology 2 is taken AFTER Fetuses, it will override them, so you CAN'T fire missiles and bombs anymore.
Technology: Stacks. If stacked with Technology then two lasers from both items will fire from each eye; however, Technology's fire rate is dependent on your tear fire rate.Additionally, the laser from Technology 2 will pass over obstacles. (Not sure if the order they are obtained matters; also not sure if Ouija Board causes this; with Technology 2 and Ouija Board alone the laser will not pass over obstacles.) Note: If you are using Cain, Technology and Technology 2 do not stack. In fact it does nothing extra and only has another Technology texture behind Cain's eye patch. Maybe the laser cannot pierce eye patches?
The Candle: Warning. The Candle will not fire. Pressing space will raise the candle over your head, but it is impossible to release the flame. Pressing space again will lower the Candle, so it's not gamebreaking, just useless. If you're holding the candle above your head and hold an arrow, enemies will still be damaged by the laser - but you won't see the laser.
The Tick: Removes it if you have it; unknown whether all of The Tick's effects disappear upon removal (health restore is definitely removed).
Mutant Spider: Stacks, keeping the 4 shots and the laser. If you have both Technology 2 and Ipecac, Mutant Spider does not add any effect.
The Inner Eye: Stacks, same as Mutant Spiders. You keep the triple shot.
Mom's Contacts: Stacks. Technology 2 will also freeze the enemies, allowing to nearly keeping them stunned permanently.
The Mulligan: Stacks. Technology 2 hits enemies multiple times for small damage really quickly. Each hit has a chance to spawn a Blue Fly; this can potentially release a large amount of Blue Flies in a short amount of time.
Polyphemus: Stacks. Still gives Polyphemus' huge tears, which fire at about the same rate as the with Polyphemus alone, or the rate of the smaller tears with Technology 2 alone. More importantly, the damage dealt by Technology 2's laser is tremendously increased, killing normal enemies in a short fraction of a second and most bosses in a few seconds, making the game extremely easy. [At least if Polyphemus is taken after Technology 2: not sure if it works like this if Polyphemus is taken first.] If playing as Cain, the huge tears will not be fired, but the power of Technology 2's laser will still be dramatically increased.
Pinky Eye: When used on Cain, he will not shoot tears because of his eye patch and thus he will not be able to poison enemies. Same with Tech 2 + Polyphemus.
Loki's Horns: Constant laser, no tears. (Bug?)
Chocolate Milk: Allows you to charge your laser. When fully charged, beam grows in size and damage. EDIT: Doesn't work. Charge only tears. Unless on Cain where laser still charges to increase damage, likely due to him only firing the laser