Seems to happen randomly when joining servers, after it happens once, Minecraft needs to be restarted for it to work again. This ONLY happens on servers, and looking around seems to change the blocks I see on the whole screen. I can still walk around normaly, I don't fall through the world or anything, which probably means the world is loaded, it just isn't showing me.
Environment
Windows 7, 64bit, Intel Core i3 540, AMD Radeon HD 3870, Java 8 update 77
Follow the steps at MC-62958 to fix your issue.