Dreadlight

Dreadlight turns your world into somewhere you don't want to be alone.
A lightweight horror shader for Minecraft, compatible with Iris and OptiFine. It crushes ambient lighting so torches and lava become your only real lifeline, wraps distant terrain in a suffocating fog, and layers film grain, subtle chromatic aberration and an unstable light flicker on top for a found-footage kind of dread.
Features

Crushed ambient lighting — real darkness, not just dim
Creeping fog that swallows the horizon
Film grain + chromatic aberration for an unsettling look
Tightening vignette
Occasional flicker, like a torch about to die
Every value adjustable in-game (Shader Options): fog density, grain, darkness, vignette, flicker

No heavy shadows or GPU cost — just pure, oppressive atmosphere. Perfect for horror maps, atmospheric survival worlds, and creepy let's-plays.