Minecraft 1.9 visual bug for me....

On reading the 1.9 notes for Minecraft I was glad to see all the update and changes listed. It all seemed to good. Changes previously have always been great with MC, always filled with additions and tweaks for the better. However MC 1.9 on initial logging in has made my old worlds unplayable. It's all down to rendering. It's like the view distance has been reduced to zero... It sucks. I've messed about with changing the settings but without much improvement. If this is more intentional I hope it's not to push older worlds out of existence.