Realistic Dark

Attempts to faithfully recreate how your actual, real-life eyes see in the dark rather than just turning down the brightness In the dark, saturation (colorfulness) is completely lost, what you see becomes blurrier and noisier (configurable in the shader settings), and the darkest color defaults not to true black, but to eigengrau (also configurable). I'm not too experienced with writing specifically Iris/Oculus shaders, so the light areas are also different from vanilla in this shader, but I think it nevertheless looks good :) I've only tested this shader on 1.19.2 (same version as the [DREAD horror modpack](https://www.curseforge.com/minecraft/modpacks/dread-arrenek); not a coincidence), but it should probably work on other versions of Minecraft that Iris/Oculus support. Inspiration fr...