Stress and tiredness are 2 things I would consider.
My eyes started to hurt again yesterday. (3rd or 4th time in 2 weeks) But I know I am really lacking a good night's sleep and have a lot of cathing up to di, which hopefully starts tomorrow when my new bed finally arrives. (only been waiting since I moved in May)
Plus stress (in my case), they say moving home is sometimes the most stress people go through, I didnt believe that at 1st, but I do now. The moving bit wasnt too bad. It's all the hassle of organising it, some of it was smooth and other bits were a night mare. Gladly that looks like all loose ends will be tied up by the end of the month.
Finace is annother one. Thinking over some of your posts in the last few months Martin you have had a few issues like the rest of us. Maybe a visit to the optician rather than the Doctor would be more benificial. That have all the equipment, it could be something or nothing. Stress, fatigue, finance.
Either way, worth checking out

(Keep us informed)