Vertical Double Vision

I had vertical double vision in my right eye for the first time a few months ago, shortly after spinal cord untethering surgery.  I was quite alarmed at the time and phoned my doctor who said that it sounded as if something had become detached in my eye.  Over the next few hours, it improved until it was back to normal.  
Since then I've had what I thought were blurry watery eyes when looking at my PC screen.  In the last week I've done some experimenting and found that the vertical double vision has occured in my right eye, particularly when I am tired.  Yesterday, my partner thought my right eye was drooping although I couldn't feel anything.
This morning, my right eye is fine but I have vertical diplopia in my left eye!  I can't understand how this could alternate to another eye and the original right eye see perfectly again.
I have had difficult to control raised blood pressure for some 8 years in the past but it is now within normal range due to a combination of medicines.
I have an underactive thyroid gland which is treated with thyroxine.
I have had a recent problem of painful swelling of my fingers in the morning which is being treated with diurectics.
I was told yesterday when I had a follow up MRI scan of my spine that there what looks like a mass of fluid but I'm still waiting for this to be fed back to the consultant.
I have an appointment with my doctor next Wednesday but would appreciate some advice.

[Ray T Oyakawa, MD]

You need to see an ophthalmologist.

Dr. O.

[caregiver222]

You have a so-called "palsy" in a cranial nerve. The intermitant nature of the problem and the fact it switches from one eye to the other strongly suggests a diabetic etiology. You need a glucose tolerance test, an Hba1c, and blood sugar monitoring.