Light
Light in the Deep Void isn't permanent. Anything that has a light level higher than 0 (with some exceptions) will attract unwanted attention. Damneds hate light and will try to break any near them. Sometimes Damneds can even spawn around light sources. The Stalking Stalker will also break lights near it. The Player needs to constantly watch over their lights, or else they will break and nothing will drop, losing them permanently.
(Versions before 1.75 !)
Light in the Deep Void isn't permanent. Anything that has a light level higher than 0 (with some exceptions) will eventually break. When in the process of breaking, Dark Tear particles will appear above the torch. After exactly 7 seconds, if there are no Players nearby, the light will break. When a Player is nearby, the timer will reset. Invisible entities know as Tiny Light, Light and Big Light appear on top of any light sources in the Deep Void and ensure that this system works.
Some light sources do not get destroyed in the Void. These include the Ferryman's Lantern, Beacon, Eye Vines, Voidlights, Dead Ferryman, Big Eyes and Voidrium Glass. If the config is set to true, Soul Lights will also never break. Safe lights do not scare off the Stalker, unlike regular lights.
When under y=0, lights will never break, even if the Player isn't near them. Instead, Shadows will spawn around the lights and begin slowly walking toward the light sources. When near, Shadows will break the light source and despawn. When a Player is inside light under y=0, the Darkness fog will become less thick around them.