Permanannt "Aura" and visual disturbances following a migraine.

Following a migraine back in march this year ive had permanant visual disturbances. Im a 22 year old female and been living with migraines for 11 years. I have never had any visual symptoms before now.
I seemed to see a "ring" or a halo in the centre of my vision, circular in shape like the outline of my iris, dark with an illuminated glow. I could see this when i fixed my eyes to one spot and turned my head from left to right.
It then became more aparant without fixating my gaze whem my heart rate was elevated, tired or before i had a migraine.
I have been back and forth to doctos, opticians, opthamologist, neuro-opthalmists and retina specialists, The first opthalologist I saw said i had swollen nerves and referred me for an MRI scan which was clear. All of the other doctors have said my eys are healthy and my vision is fine so have since been distorted. I now have a permanant blurred spot in my left eye. It is not central but more off to the left, nor is it black in colour. The patch is a oval like shape but it is not black, more of a light grey in colour. The best was to describe it would be if you were wearing a pair of glassed and a drop of water was on the left lense but not on the centre but over to the left. You can see through the drop but its as bit blurry and whats in it is distorted and its slighty darker than normal vision. When i close my eye I can still see the "patch" but it is like a camera flash slill embedded and thats what it is contantly.I have now noticed another small patch forming in the same area of my right eye.
i have all the symptoms of hypertension. Most mornings i wake up with "pulsing vision" where my sight seems to be "jumping" in time with my pulse. I have burred spots, feel a heavy pressure in my head, have visual disturbances and hear a constant wooshing sound in my ears in conjunction with my pulse. I am also in the right age range, female and overweight.

Any ideas as to what this might be?

[Michael J Kutryb, MD]

Usually an MRI and MRA would reveal any stroke or aneurysm or tumor that could be to blame. I suppose there could be a quite small area of permanant cellular damage to the optic nerve or retina or visual cortex of the brain that is too small to pick up on these studies.  Also you should be evaluatated for idiopathic intracranial hypertension also called psudodtumor cerebri which would require a lumbar punture test (spinal tap.)