Sinus Shader is a Minecraft Optifine/Iris Shader that makes the game render in a Sine Wave.
It is a interesting distortion effect and I like sine waves. The effect is customizable, you can set the direction from horizontal(0 in V1 | 1, 2 in V2) to vertical(1 in V1 | 3, 4 in V2), the frequency and the height(attitude). This Shader is completely useless and has no reason to exist, but you can use it anyways. Maybe it could be an interesting challenge, or something, idk. Have fun with the Shader and the motion sickness it causes.
Version 2 also features customizable movement(left to right, right to left, top to bottom, bottom to top) and the option to only apply the effect if you are under water. I added that because I actually think it kinda looks like a good under water effect with the right settings.