Hi
I wonder if this is any help? Some years ago I suffered with blurred vision. I couldn't stand the artificial light in large stores and I had a small fuzzy spot on the edge of my vision. Over a period of months I went to the opticians on several occasions but they could find nothing wrong. Eventually my optician sent me to the emergency eye clinic at our local hospital, because my symptoms could have been a indication of the retina about to detach. This is where it gets interesting. After a very extensive exam the doctor told me a was suffering from a migraine. This had been ticking away for months, at a low level. I have since found out this is know as a 'silent migraine', as you have all the visual symptoms but no head pain. The doctor told me it was probably food related and I should experiment to find the trigger. I was very lucky as I dropped caffeine as my first choice. Within 48 hours my vision had cleared. The only downside was a thumping headache for a week but it was well worth it.
This may not be what is causing your problem but won't do any harm to try dropping known migraine triggers from your diet (one at a time) and see if it helps. Google 'silent migraine' and see if it matches your problem.
Good luck
