"Changing the Mipmap Levels"

How to do it :
-Clic on "Options..." --> "Video Settings..." --> Change your "Mipmap Levels" to OFF --> "Done" --> "Done" --> "Back to game" : the world is normal but then,
-Clic on "Options..." --> "Video Settings..." --> Change your "Mipmap Levels" to 4 Normally, you have the same menu I have on screenshot #1 --> "Done" --> "Done" --> "Back to game" It does not work any time but, most of time, you have for few sec the same world "green and white" that I have on screenshot #2