I'm having a strange gaphical glitch where a somewhat Skybox-colored glitch cover the screen, sometime little sometime a lot. The glitch is "stable" as long as you are not moving the view.
I've also noticed "glitch pillars" shooting to the sky.

I haven't done anything unusual with my computer or minecraft's graphic options, but i happened shortly after i turned off the sounds.

This could be a skybox error.

Any kind of rendering update, such as switching render distance or turning openGL on or off, fix the glitch.