I have a problem with my binocular vision. The muscles that are responsible for moving my eyes outwards are very weak, much weaker than the muscles that move my eyes inwards. When I am very tired, I can’t focus on people or things that are far away. I start seeing doubled monsters with extra eyes and noses.
Luckily, instead of looking scary, the monsters look familiar. In fact, they look exactly like Picasso’s portraits. I bet Picasso had problems with his eye muscles.