Long term headaches

My wife has been getting dull (not sharp) headaches on and off for 2 years now, and she told me the other day that they are much worse than 2 years ago. There have been weeks / months where she has not had them, but then they return. She tells me that when she gets the headaches, the pain is behind the eyes, but is a dull ache which is worse than 2 years ago. In the past couple of months she has had 2 or 3 bouts of blurred vision in her right eye which only lasts about 5 minutes, then she can see okay again.

She has been to the Doctor several times and has kept a diary. Yesterday, she had a full eye test. Everything with regard to her eyes was 20/20. She was worried yesterday because she couldn't remember how to spell our House Name, but this is the only memory loss that I have noticed from her.

She is seeing the Doctor again tomorrow, but we are both very worried that it might be something sinister, however, there is no genetic history of this in her family.

Have you any thoughts?