Euthanasia: Needles from Euthanasia bursts will move towards Isaac.
Flat Stone: Tears bounce away from and then back towards Isaac. However, unless you have range ups, this generally results in tears slowing down then dissipating rather than actually returning.
Haemolacria: Range becomes extremely high, making Haemolacria tears follow Isaac for a long time before hitting the ground. Burst tears do not have a boomerang effect.
Ipecac: Not recommended. The explosive tears will begin flying back towards Isaac after having reached a certain distance.
Lachryphagy: Tears will move towards Isaac and can still be fed and burst. The bursted tears will also move towards Isaac.
A Lump of Coal: The tears increase in damage as they are pulled towards Isaac.
The Ludovico Technique: The tear will slowly move towards Isaac, and the shot speed increase allows the tear to be moved much faster.
Mom's Knife: No effect, as the knife already has this effect.
The stat changes carry over, but the knife's trajectory does not.
Montezuma's Revenge: Causes the beam range behind Isaac to become significantly increased as well as having a short range similar to Azazel's beam in front of him. This greatly eases the use of this item allowing for high DPS.
Damage and luck changes stack, range and shot speed don't.
Piercing tears: Despite the piercing effect, tears cannot damage the same enemy multiple times.
Pop!: Tears constantly swarm around Isaac, quickly filling the room.
Proptosis: At base tear size, tears disappear before they can return to Isaac.
Pupula Duplex: Tears will spin like boomerangs, the effect is purely cosmetic.
Revelation: The laser makes a thin loop in front of Isaac, and fires the normal laser backwards.
Rubber Cement: Isaac's tears will continually be pulled towards him, effectively reducing the chances that tears will bounce.
Spoon Bender: If tears are close enough to an enemy, it will home in and damage them. If not, they will return to Isaac.
Strange Attractor: Not recommended. While it may make it easier to hit enemies, it also makes it much easier for them to be attracted to Isaac, surrounding him.
This item is a reference to the concept of a mirror breaking when being looked into, usually played as a joke on ugly characters being 'so ugly they break the mirror'.
This may be a commentary on Isaac's poor self-esteem.
The Luck Down inflicted by the item is a secondary reference to the superstition of a broken mirror causing seven years of bad luck.
In his first post-Repentance Lore Stream, Edmund McMillen stated that Isaac's visual appearance (ie: the crescent shape on his forehead) is simply a reference to the shape of boomerangs, as the item causes Isaac's tears to come back to him like the movement pattern of a boomerang.
In the same lore stream, McMillen explained that the reason Isaac's tears return to him is simply due to the idea of attacking a mirror, with the tears being reflected backwards similarly to how shiny surfaces (such as mirrors) reflect light.
This item is the only one to apply a multiplier to Isaac's shot speed, instead of a plain bonus.
+1.5 range.
2x + 1.5 range, +1.5 damage, -1 luck.
Anti-Gravity: The tears will slowly move towards Isaac instead of remaining stationary. Releasing the fire button will launch the tears as usual.
Brimstone: Overrides My Reflection.
Makes the beam curve when moving. It has the same effect on Azazel's mini-brimstone and doubles the range.
Continuum: If tears cross the border of the room, they will move towards Isaac from their new position rather than crossing back across the border.
Compound Fracture / 
The Parasite/
Cricket's Body: Split tears will move towards Isaac.
Dr. Fetus: Not recommended. The bombs will slide back towards Isaac after having reached a certain distance.
Rocket in a Jar, the rockets will not explode unless they hit an obstacle or enemy, making this much safer.
Epic Fetus: Overrides My Reflection.
Euthanasia: Needles from Euthanasia bursts will move towards Isaac.
Flat Stone: Tears bounce away from and then back towards Isaac. However, unless you have range ups, this generally results in tears slowing down then dissipating rather than actually returning.
Haemolacria: Range becomes extremely high, making Haemolacria tears follow Isaac for a long time before hitting the ground. Burst tears do not have a boomerang effect.
Ipecac: Not recommended. The explosive tears will begin flying back towards Isaac after having reached a certain distance.
Lachryphagy: Tears will move towards Isaac and can still be fed and burst. The bursted tears will also move towards Isaac.
A Lump of Coal: The tears increase in damage as they are pulled towards Isaac.
The Ludovico Technique: The tear will slowly move towards Isaac, and the shot speed increase allows the tear to be moved much faster.
Mom's Knife: No effect, as the knife already has this effect.
Montezuma's Revenge: Causes the beam range behind Isaac to become significantly increased as well as having a short range similar to Azazel's beam in front of him. This greatly eases the use of this item allowing for high DPS.
My Reflection: No further stat changes.
Pop!: Tears constantly swarm around Isaac, quickly filling the room.
Proptosis: At base tear size, tears disappear before they can return to Isaac.
Pupula Duplex: Tears will spin like boomerangs, the effect is purely cosmetic.
Revelation: The laser makes a thin loop in front of Isaac, and fires the normal laser backwards.
Rubber Cement: Isaac's tears will continually be pulled towards him, effectively reducing the chances that tears will bounce.
Spoon Bender: If tears are close enough to an enemy, it will home in and damage them. If not, they will return to Isaac.
Strange Attractor: Not recommended. While it may make it easier to hit enemies, it also makes it much easier for them to be attracted to Isaac, surrounding him.
Technology: Overrides My Reflection.
Technology 2 / 
Tech.5
Tech X: Stat effects of My Reflection remain but the boomerang effect does not.
Tiny Planet: The orbital tears will move faster to stay in orbit around Isaac, making aiming easier.
Trisagion: Makes the beams much longer as they move away from and then back towards Isaac.
Whip Worm: Further increases shot speed, making Isaac's tears travel much farther forward before returning to Isaac.
The Binding of Isaac: Rebirth
