The Operative Word Is Afraid

Speaking of eye-crossing. I'm afraid my double vision is coming back. All day long, I find my vision going double. With conscious effort, I can easily pull the images back together. But it's happening, nevertheless. It's hard to describe to someone else -- I can actually feel the muscles in my eyes relaxing and letting my vision wander. It's got to be the same muscle weakness that led to my serious diplopia before. So what's going on? Is it a relapse? Or is it caused by the fact that I am exhausted and sitting at the computer too much? I didn't expect this.