I was thoroughly investigated last year for similar by a Neuro- ophthalmologist in East Melbourne
@RooFlyer.
Had the (bad) habit of reading my phone in the early hours.
My right eye would have virtually no vision for 10 minutes or more but this would gradually resolve when I closed my eyes.
As I only have full vision in my right eye (left eye minimal sight since birth), this was of great concern.
After every test known to man, given the all clear.
Hope it is the same for you.
Happy to PM the name of the A/Professor I saw.
Note: I do not use my phone overnight now and do not turn bright bathroom light on - eye is okay overnight, but if I do use phone particularly I have issues.