There is one thing guaranteed to gum up a writer's works (excuse the pun). A pinched nerve in the neck. I can type looking at the screen just fine as long as I a) do a neck roll every 2.5 minutes b) don't have to look down at the keys for any reason. Of course my mind has taken the opportunity to spew ideas which I can only jot down on pieces of paper and hope I remember them when the spinal column decides to behave. I'm almost wishing for writer's block. Almost.