Left eye does not open in morning

Every morning, when I first wake up, my left eyelid remains closed.   This has happened every morning for the past 4 months.   The duration of time before my eyelid opens is approx.  5 minutes and then it opens very slowly.  It is not stuck...  the eyelid just does not open.  After it does open both of my eyes are fine for the rest of the day. This strange eye closure has now started to occur after a long nap..over 2 hours.   I am a 55 year old female and have had successful cataract surgery on both eyes.  The surgery on my left eye was done 18 months ago. I have no other health issues.  So far I have seen both my optometrist and an ophthalmologist.   Neither have any answers to why this is occurring.   The ophthalmologist said that apart from some evidence of dryness in both of my eyes, the eyes and muscles of the eyes appear healthy.   I know have an appointment to see a neuro-ophthalmologist come October.   Have you heard of this before?  Any thoughts as to why this is happening?

[Forum-OD-MP]

well not that exact symptom...but yet, i have definitely heard of people with muscle weakness in an eyelid.

the possibilities include:  myasthenia gravis, graves disease, and other neurological disorders.  you are doing the right thing by seeing a neurologist.  thats the next step

[gailb714]

A related discussion, could not open my left eye was started.