20/20

20/20 is a passive item.

Effect

 * Isaac fires two tears at once, one from each eye.
 * 0.75x damage multiplier.

Synergies

 * / : Every second row of tears has increased damage.
 * : Two Brimstone shots are fired, without an increase in charge time.
 * Every additional 20/20 adds 2 more tears in a tight pattern.
 * Adds one more tear without further lowering damage.
 * / : Replaces the single missile strike with a barrage of two consecutive missiles.
 * / : Adds two/three tears to each shot, with no extra fire rate decrease.
 * Adds one tear to each shot, with no extra fire rate decrease.
 * : Fires 5 tears with no fire rate decrease.
 * Fires 4 tears with no fire rate decrease.
 * : The Ludovico tear gains one smaller tear orbiting the main one, each dealing the same amount of damage.
 * : Adds two tears to the tear barrage, for a total of 16.
 * : Fires two tears at once that almost completely overlap each other.
 * Fires 5 tears with no fire rate decrease.
 * Fires two technology shots simultaneously.
 * : Both tears are fired along the beam. Only one tear can be seen, as they overlap each other.
 * : Two tears are fired in each direction.

Interactions

 * : Overrides 20/20.
 * : Overrides 20/20.
 * Increase number of tears in tear barrage; however, only fires one stone.
 * Only occasionally fires one tear in the other three directions.
 * Only occasionally fires one tear out of the back of Isaac's head.
 * : Overrides 20/20.
 * : Overrides 20/20.
 * : Overrides 20/20.
 * : Does not affect the number of tears when bombs explode.
 * : Overrides 20/20.
 * : No effect on number of tears when taking damage.

Trivia

 * 20/20 is an idiom that refers to someone with near-perfect vision.
 * Despite only having one eye, Cain shoots two tears at once with this item.
 * This item is used in Seeing Double (challenge #40).

Seeds
77H1 T20K (Treasure Room adjacent to spawn) STDX QSC8 (Treasure Room adjacent to spawn) NYJK 3QDN (Treasure Room adjacent to spawn) AFJE 9RXX (Treasure Room adjacent to spawn) Y6FY DZH6 (Treasure Room next to spawn) GD7V 66ZX (Treasure Room adjacent to spawn) 92SM AXWG (Treasure Room next to spawn) H3Y3 X22S (First floor Treasure Room) 228H QN22 (First floor Treasure Room above spawn) GBDPZXGJ (Eden starts with it)