Since the 1.7.10 update, in both Single Player and Minecraft Realms play, I am experiencing a ton of pixelation or item flashing. My active inventory bar contents are flashing, and when I open my 'E' inventory, the screen is likewise flashing (going very bright to very dim, with particles appearing randomly all about the edges) and sometimes (infrequently) I will see what looks like ghosted or artifact-ed images of all of the possible inventory item sprites. (I think that I can see in these flashes the spawner eggs you would see in Creative, but we're in Survival, but it's a very brief flash).

The behavior seems to be causing some lag and does make game play a bit challenging, especially when hostile mobs are interacted with.

I have included screencaps of my in-game Video Settings, and two screencaps where I try and capture the behavior; I'll see if I can figure out how to video cap it.

In image 08.54.01, you can that the item in my fifth active spot (a Bow) has phased out; in image 08.53.54, you can the Bow has returned but there is now a white "command prompt" artifact in the upper left hand corner.