The blurred vision appeared when my character was more famished. In addition, a friend hit me with axe, unintentionally, so I used bandages on my character and I ate, I had no message but blurred vision persisted.
(i'm french, sorry for my bad english)
That's what happens whe you're low on health. Not blood but health. Try to get bright green energized and hydrated status.
As pigmej said, this is not a bug. You need to eat and drink until you have bright green hydrated and energized bars, and then you will see a HEALING bar in your inventory.
But it is importent to eat BEFORE and to drink AFTER.
if everything is grey, 10 cans of beans is enough. All the rest is water, until you are "stuffed".